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Publisher: John Wiley and Sons   (Total: 1583 journals)

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Showing 1 - 200 of 1583 Journals sorted alphabetically
Abacus     Hybrid Journal   (Followers: 12, SJR: 0.48, h-index: 22)
About Campus     Hybrid Journal   (Followers: 5)
Academic Emergency Medicine     Hybrid Journal   (Followers: 54, SJR: 1.385, h-index: 91)
Accounting & Finance     Hybrid Journal   (Followers: 44, SJR: 0.547, h-index: 30)
ACEP NOW     Free  
Acta Anaesthesiologica Scandinavica     Hybrid Journal   (Followers: 50, SJR: 1.02, h-index: 88)
Acta Archaeologica     Hybrid Journal   (Followers: 141, SJR: 0.101, h-index: 9)
Acta Geologica Sinica (English Edition)     Hybrid Journal   (Followers: 3, SJR: 0.552, h-index: 41)
Acta Neurologica Scandinavica     Hybrid Journal   (Followers: 5, SJR: 1.203, h-index: 74)
Acta Obstetricia et Gynecologica Scandinavica     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 81)
Acta Ophthalmologica     Hybrid Journal   (Followers: 5, SJR: 0.112, h-index: 1)
Acta Paediatrica     Hybrid Journal   (Followers: 54, SJR: 0.794, h-index: 88)
Acta Physiologica     Hybrid Journal   (Followers: 7, SJR: 1.69, h-index: 88)
Acta Polymerica     Hybrid Journal   (Followers: 9)
Acta Psychiatrica Scandinavica     Hybrid Journal   (Followers: 35, SJR: 2.518, h-index: 113)
Acta Zoologica     Hybrid Journal   (Followers: 5, SJR: 0.459, h-index: 29)
Acute Medicine & Surgery     Hybrid Journal   (Followers: 2)
Addiction     Hybrid Journal   (Followers: 32, SJR: 2.086, h-index: 143)
Addiction Biology     Hybrid Journal   (Followers: 11, SJR: 2.091, h-index: 57)
Adultspan J.     Hybrid Journal   (SJR: 0.127, h-index: 4)
Advanced Energy Materials     Hybrid Journal   (Followers: 24, SJR: 6.411, h-index: 86)
Advanced Engineering Materials     Hybrid Journal   (Followers: 25, SJR: 0.81, h-index: 81)
Advanced Functional Materials     Hybrid Journal   (Followers: 49, SJR: 5.21, h-index: 203)
Advanced Healthcare Materials     Hybrid Journal   (Followers: 13, SJR: 0.232, h-index: 7)
Advanced Materials     Hybrid Journal   (Followers: 253, SJR: 9.021, h-index: 345)
Advanced Materials Interfaces     Hybrid Journal   (Followers: 6, SJR: 1.177, h-index: 10)
Advanced Optical Materials     Hybrid Journal   (Followers: 5, SJR: 2.488, h-index: 21)
Advanced Science     Open Access   (Followers: 4)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17, SJR: 2.729, h-index: 121)
Advances in Polymer Technology     Hybrid Journal   (Followers: 13, SJR: 0.344, h-index: 31)
Africa Confidential     Hybrid Journal   (Followers: 19)
Africa Research Bulletin: Economic, Financial and Technical Series     Hybrid Journal   (Followers: 12)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 9)
African Development Review     Hybrid Journal   (Followers: 33, SJR: 0.275, h-index: 17)
African J. of Ecology     Hybrid Journal   (Followers: 14, SJR: 0.477, h-index: 39)
Aggressive Behavior     Hybrid Journal   (Followers: 15, SJR: 1.391, h-index: 66)
Aging Cell     Open Access   (Followers: 9, SJR: 4.374, h-index: 95)
Agribusiness : an Intl. J.     Hybrid Journal   (Followers: 6, SJR: 0.627, h-index: 14)
Agricultural and Forest Entomology     Hybrid Journal   (Followers: 14, SJR: 0.925, h-index: 43)
Agricultural Economics     Hybrid Journal   (Followers: 44, SJR: 1.099, h-index: 51)
AIChE J.     Hybrid Journal   (Followers: 29, SJR: 1.122, h-index: 120)
Alcoholism and Drug Abuse Weekly     Hybrid Journal   (Followers: 7)
Alcoholism Clinical and Experimental Research     Hybrid Journal   (Followers: 7, SJR: 1.416, h-index: 125)
Alimentary Pharmacology & Therapeutics     Hybrid Journal   (Followers: 34, SJR: 2.833, h-index: 138)
Alimentary Pharmacology & Therapeutics Symposium Series     Hybrid Journal   (Followers: 3)
Allergy     Hybrid Journal   (Followers: 49, SJR: 3.048, h-index: 129)
Alternatives to the High Cost of Litigation     Hybrid Journal   (Followers: 3)
American Anthropologist     Hybrid Journal   (Followers: 128, SJR: 0.951, h-index: 61)
American Business Law J.     Hybrid Journal   (Followers: 24, SJR: 0.205, h-index: 17)
American Ethnologist     Hybrid Journal   (Followers: 91, SJR: 2.325, h-index: 51)
American J. of Economics and Sociology     Hybrid Journal   (Followers: 28, SJR: 0.211, h-index: 26)
American J. of Hematology     Hybrid Journal   (Followers: 31, SJR: 1.761, h-index: 77)
American J. of Human Biology     Hybrid Journal   (Followers: 12, SJR: 1.018, h-index: 58)
American J. of Industrial Medicine     Hybrid Journal   (Followers: 16, SJR: 0.993, h-index: 85)
American J. of Medical Genetics Part A     Hybrid Journal   (Followers: 15, SJR: 1.115, h-index: 61)
American J. of Medical Genetics Part B: Neuropsychiatric Genetics     Hybrid Journal   (Followers: 3, SJR: 1.771, h-index: 107)
American J. of Medical Genetics Part C: Seminars in Medical Genetics     Partially Free   (Followers: 5, SJR: 2.315, h-index: 79)
American J. of Orthopsychiatry     Hybrid Journal   (Followers: 4, SJR: 0.756, h-index: 69)
American J. of Physical Anthropology     Hybrid Journal   (Followers: 36, SJR: 1.41, h-index: 88)
American J. of Political Science     Hybrid Journal   (Followers: 248, SJR: 5.101, h-index: 114)
American J. of Primatology     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 63)
American J. of Reproductive Immunology     Hybrid Journal   (Followers: 3, SJR: 1.347, h-index: 75)
American J. of Transplantation     Hybrid Journal   (Followers: 15, SJR: 2.792, h-index: 140)
American J. on Addictions     Hybrid Journal   (Followers: 9, SJR: 0.843, h-index: 57)
Anaesthesia     Hybrid Journal   (Followers: 115, SJR: 1.404, h-index: 88)
Analyses of Social Issues and Public Policy     Hybrid Journal   (Followers: 11, SJR: 0.397, h-index: 18)
Analytic Philosophy     Hybrid Journal   (Followers: 16)
Anatomia, Histologia, Embryologia: J. of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3, SJR: 0.295, h-index: 27)
Anatomical Sciences Education     Hybrid Journal   (Followers: 1, SJR: 0.633, h-index: 24)
Andrologia     Hybrid Journal   (Followers: 2, SJR: 0.528, h-index: 45)
Andrology     Hybrid Journal   (Followers: 2, SJR: 0.979, h-index: 14)
Angewandte Chemie     Hybrid Journal   (Followers: 155)
Angewandte Chemie Intl. Edition     Hybrid Journal   (Followers: 211, SJR: 6.229, h-index: 397)
Animal Conservation     Hybrid Journal   (Followers: 34, SJR: 1.576, h-index: 62)
Animal Genetics     Hybrid Journal   (Followers: 8, SJR: 0.957, h-index: 67)
Animal Science J.     Hybrid Journal   (Followers: 6, SJR: 0.569, h-index: 24)
Annalen der Physik     Hybrid Journal   (Followers: 5, SJR: 1.46, h-index: 40)
Annals of Anthropological Practice     Partially Free   (Followers: 2, SJR: 0.187, h-index: 5)
Annals of Applied Biology     Hybrid Journal   (Followers: 8, SJR: 0.816, h-index: 56)
Annals of Clinical and Translational Neurology     Open Access   (Followers: 1)
Annals of Human Genetics     Hybrid Journal   (Followers: 9, SJR: 1.191, h-index: 67)
Annals of Neurology     Hybrid Journal   (Followers: 43, SJR: 5.584, h-index: 241)
Annals of Noninvasive Electrocardiology     Hybrid Journal   (Followers: 2, SJR: 0.531, h-index: 38)
Annals of Public and Cooperative Economics     Hybrid Journal   (Followers: 9, SJR: 0.336, h-index: 23)
Annals of the New York Academy of Sciences     Hybrid Journal   (Followers: 5, SJR: 2.389, h-index: 189)
Annual Bulletin of Historical Literature     Hybrid Journal   (Followers: 12)
Annual Review of Information Science and Technology     Hybrid Journal   (Followers: 14)
Anthropology & Education Quarterly     Hybrid Journal   (Followers: 24, SJR: 0.72, h-index: 31)
Anthropology & Humanism     Hybrid Journal   (Followers: 16, SJR: 0.137, h-index: 3)
Anthropology News     Hybrid Journal   (Followers: 14)
Anthropology of Consciousness     Hybrid Journal   (Followers: 11, SJR: 0.172, h-index: 5)
Anthropology of Work Review     Hybrid Journal   (Followers: 11, SJR: 0.256, h-index: 5)
Anthropology Today     Hybrid Journal   (Followers: 93, SJR: 0.545, h-index: 15)
Antipode     Hybrid Journal   (Followers: 44, SJR: 2.212, h-index: 69)
Anz J. of Surgery     Hybrid Journal   (Followers: 6, SJR: 0.432, h-index: 59)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apmis     Hybrid Journal   (Followers: 1, SJR: 0.855, h-index: 73)
Applied Cognitive Psychology     Hybrid Journal   (Followers: 67, SJR: 0.754, h-index: 69)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7, SJR: 0.632, h-index: 58)
Applied Psychology     Hybrid Journal   (Followers: 137, SJR: 1.023, h-index: 64)
Applied Psychology: Health and Well-Being     Hybrid Journal   (Followers: 48, SJR: 0.868, h-index: 13)
Applied Stochastic Models in Business and Industry     Hybrid Journal   (Followers: 5, SJR: 0.613, h-index: 24)
Aquaculture Nutrition     Hybrid Journal   (Followers: 13, SJR: 1.025, h-index: 55)
Aquaculture Research     Hybrid Journal   (Followers: 31, SJR: 0.807, h-index: 60)
Aquatic Conservation Marine and Freshwater Ecosystems     Hybrid Journal   (Followers: 34, SJR: 1.047, h-index: 57)
Arabian Archaeology and Epigraphy     Hybrid Journal   (Followers: 11, SJR: 0.453, h-index: 11)
Archaeological Prospection     Hybrid Journal   (Followers: 12, SJR: 0.922, h-index: 21)
Archaeology in Oceania     Hybrid Journal   (Followers: 13, SJR: 0.745, h-index: 18)
Archaeometry     Hybrid Journal   (Followers: 27, SJR: 0.809, h-index: 48)
Archeological Papers of The American Anthropological Association     Hybrid Journal   (Followers: 14, SJR: 0.156, h-index: 2)
Architectural Design     Hybrid Journal   (Followers: 25, SJR: 0.261, h-index: 9)
Archiv der Pharmazie     Hybrid Journal   (Followers: 4, SJR: 0.628, h-index: 43)
Archives of Drug Information     Hybrid Journal   (Followers: 4)
Archives of Insect Biochemistry and Physiology     Hybrid Journal   (SJR: 0.768, h-index: 54)
Area     Hybrid Journal   (Followers: 12, SJR: 0.938, h-index: 57)
Art History     Hybrid Journal   (Followers: 215, SJR: 0.153, h-index: 13)
Arthritis & Rheumatology     Hybrid Journal   (Followers: 49, SJR: 1.984, h-index: 20)
Arthritis Care & Research     Hybrid Journal   (Followers: 28, SJR: 2.256, h-index: 114)
Artificial Organs     Hybrid Journal   (Followers: 1, SJR: 0.872, h-index: 60)
ASHE Higher Education Reports     Hybrid Journal   (Followers: 14)
Asia & the Pacific Policy Studies     Open Access   (Followers: 14)
Asia Pacific J. of Human Resources     Hybrid Journal   (Followers: 311, SJR: 0.494, h-index: 19)
Asia Pacific Viewpoint     Hybrid Journal   (SJR: 0.616, h-index: 26)
Asia-Pacific J. of Chemical Engineering     Hybrid Journal   (Followers: 7, SJR: 0.345, h-index: 20)
Asia-pacific J. of Clinical Oncology     Hybrid Journal   (Followers: 6, SJR: 0.554, h-index: 14)
Asia-Pacific J. of Financial Studies     Hybrid Journal   (SJR: 0.241, h-index: 7)
Asia-Pacific Psychiatry     Hybrid Journal   (Followers: 3, SJR: 0.377, h-index: 7)
Asian Economic J.     Hybrid Journal   (Followers: 8, SJR: 0.234, h-index: 21)
Asian Economic Policy Review     Hybrid Journal   (Followers: 3, SJR: 0.196, h-index: 12)
Asian J. of Control     Hybrid Journal   (SJR: 0.862, h-index: 34)
Asian J. of Endoscopic Surgery     Hybrid Journal   (SJR: 0.394, h-index: 7)
Asian J. of Organic Chemistry     Hybrid Journal   (Followers: 4, SJR: 1.443, h-index: 19)
Asian J. of Social Psychology     Hybrid Journal   (Followers: 5, SJR: 0.665, h-index: 37)
Asian Politics and Policy     Hybrid Journal   (Followers: 13, SJR: 0.207, h-index: 7)
Asian Social Work and Policy Review     Hybrid Journal   (Followers: 5, SJR: 0.318, h-index: 5)
Asian-pacific Economic Literature     Hybrid Journal   (Followers: 5, SJR: 0.168, h-index: 15)
Assessment Update     Hybrid Journal   (Followers: 4)
Astronomische Nachrichten     Hybrid Journal   (Followers: 2, SJR: 0.701, h-index: 40)
Atmospheric Science Letters     Open Access   (Followers: 29, SJR: 1.332, h-index: 27)
Austral Ecology     Hybrid Journal   (Followers: 12, SJR: 1.095, h-index: 66)
Austral Entomology     Hybrid Journal   (Followers: 10, SJR: 0.524, h-index: 28)
Australasian J. of Dermatology     Hybrid Journal   (Followers: 8, SJR: 0.714, h-index: 40)
Australasian J. On Ageing     Hybrid Journal   (Followers: 7, SJR: 0.39, h-index: 22)
Australian & New Zealand J. of Statistics     Hybrid Journal   (Followers: 13, SJR: 0.275, h-index: 28)
Australian Accounting Review     Hybrid Journal   (Followers: 4, SJR: 0.709, h-index: 14)
Australian and New Zealand J. of Family Therapy (ANZJFT)     Hybrid Journal   (Followers: 3, SJR: 0.382, h-index: 12)
Australian and New Zealand J. of Obstetrics and Gynaecology     Hybrid Journal   (Followers: 43, SJR: 0.814, h-index: 49)
Australian and New Zealand J. of Public Health     Hybrid Journal   (Followers: 11, SJR: 0.82, h-index: 62)
Australian Dental J.     Hybrid Journal   (Followers: 6, SJR: 0.482, h-index: 46)
Australian Economic History Review     Hybrid Journal   (Followers: 4, SJR: 0.171, h-index: 12)
Australian Economic Papers     Hybrid Journal   (Followers: 22, SJR: 0.23, h-index: 9)
Australian Economic Review     Hybrid Journal   (Followers: 6, SJR: 0.357, h-index: 21)
Australian Endodontic J.     Hybrid Journal   (Followers: 3, SJR: 0.513, h-index: 24)
Australian J. of Agricultural and Resource Economics     Hybrid Journal   (Followers: 3, SJR: 0.765, h-index: 36)
Australian J. of Grape and Wine Research     Hybrid Journal   (Followers: 5, SJR: 0.879, h-index: 56)
Australian J. of Politics & History     Hybrid Journal   (Followers: 13, SJR: 0.203, h-index: 14)
Australian J. of Psychology     Hybrid Journal   (Followers: 17, SJR: 0.384, h-index: 30)
Australian J. of Public Administration     Hybrid Journal   (Followers: 381, SJR: 0.418, h-index: 29)
Australian J. of Rural Health     Hybrid Journal   (Followers: 4, SJR: 0.43, h-index: 34)
Australian Occupational Therapy J.     Hybrid Journal   (Followers: 66, SJR: 0.59, h-index: 29)
Australian Psychologist     Hybrid Journal   (Followers: 11, SJR: 0.331, h-index: 31)
Australian Veterinary J.     Hybrid Journal   (Followers: 19, SJR: 0.459, h-index: 45)
Autism Research     Hybrid Journal   (Followers: 31, SJR: 2.126, h-index: 39)
Autonomic & Autacoid Pharmacology     Hybrid Journal   (SJR: 0.371, h-index: 29)
Banks in Insurance Report     Hybrid Journal   (Followers: 1)
Basic & Clinical Pharmacology & Toxicology     Hybrid Journal   (Followers: 10, SJR: 0.539, h-index: 70)
Basic and Applied Pathology     Open Access   (Followers: 2, SJR: 0.113, h-index: 4)
Basin Research     Hybrid Journal   (Followers: 3, SJR: 1.54, h-index: 60)
Bauphysik     Hybrid Journal   (Followers: 2, SJR: 0.194, h-index: 5)
Bauregelliste A, Bauregelliste B Und Liste C     Hybrid Journal  
Bautechnik     Hybrid Journal   (Followers: 1, SJR: 0.321, h-index: 11)
Behavioral Interventions     Hybrid Journal   (Followers: 8, SJR: 0.297, h-index: 23)
Behavioral Sciences & the Law     Hybrid Journal   (Followers: 23, SJR: 0.736, h-index: 57)
Berichte Zur Wissenschaftsgeschichte     Hybrid Journal   (Followers: 9, SJR: 0.11, h-index: 5)
Beton- und Stahlbetonbau     Hybrid Journal   (Followers: 2, SJR: 0.493, h-index: 14)
Biochemistry and Molecular Biology Education     Hybrid Journal   (Followers: 6, SJR: 0.311, h-index: 26)
Bioelectromagnetics     Hybrid Journal   (Followers: 1, SJR: 0.568, h-index: 64)
Bioengineering & Translational Medicine     Open Access  
BioEssays     Hybrid Journal   (Followers: 10, SJR: 3.104, h-index: 155)
Bioethics     Hybrid Journal   (Followers: 14, SJR: 0.686, h-index: 39)
Biofuels, Bioproducts and Biorefining     Hybrid Journal   (Followers: 1, SJR: 1.725, h-index: 56)
Biological J. of the Linnean Society     Hybrid Journal   (Followers: 14, SJR: 1.172, h-index: 90)
Biological Reviews     Hybrid Journal   (Followers: 3, SJR: 6.469, h-index: 114)
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 42, SJR: 0.12, h-index: 1)
Biology of the Cell     Full-text available via subscription   (Followers: 9, SJR: 1.812, h-index: 69)
Biomedical Chromatography     Hybrid Journal   (Followers: 6, SJR: 0.572, h-index: 49)
Biometrical J.     Hybrid Journal   (Followers: 5, SJR: 0.784, h-index: 44)
Biometrics     Hybrid Journal   (Followers: 36, SJR: 1.906, h-index: 96)
Biopharmaceutics and Drug Disposition     Hybrid Journal   (Followers: 10, SJR: 0.715, h-index: 44)
Biopolymers     Hybrid Journal   (Followers: 18, SJR: 1.199, h-index: 104)
Biotechnology and Applied Biochemistry     Hybrid Journal   (Followers: 45, SJR: 0.415, h-index: 55)
Biotechnology and Bioengineering     Hybrid Journal   (Followers: 137, SJR: 1.633, h-index: 146)
Biotechnology J.     Hybrid Journal   (Followers: 13, SJR: 1.185, h-index: 51)
Biotechnology Progress     Hybrid Journal   (Followers: 39, SJR: 0.736, h-index: 101)
Biotropica     Hybrid Journal   (Followers: 18, SJR: 1.374, h-index: 71)
Bipolar Disorders     Hybrid Journal   (Followers: 10, SJR: 2.592, h-index: 100)
Birth     Hybrid Journal   (Followers: 34, SJR: 0.763, h-index: 64)
Birth Defects Research Part A : Clinical and Molecular Teratology     Hybrid Journal   (Followers: 2, SJR: 0.727, h-index: 77)
Birth Defects Research Part B: Developmental and Reproductive Toxicology     Hybrid Journal   (Followers: 5, SJR: 0.468, h-index: 47)
Birth Defects Research Part C : Embryo Today : Reviews     Hybrid Journal   (SJR: 1.513, h-index: 55)

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Journal Cover Acta Physiologica
  [SJR: 1.69]   [H-I: 88]   [7 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1748-1708 - ISSN (Online) 1748-1716
   Published by John Wiley and Sons Homepage  [1583 journals]
  • 2016 Impact Factor for Acta Physiologica is 4.9
    • Authors: P. B. Persson
      Abstract: How should we best measure journal quality' This never-ending-question remains to be resolved, yet the impact factor receives by far most attention.1 Suggestions for better metrics (e.g. altmetrics2 or the Eigenfactor3) soon outnumbers the long list of impact factor flawsThis article is protected by copyright. All rights reserved.
      PubDate: 2017-06-21T11:01:53.39793-05:0
      DOI: 10.1111/apha.12910
       
  • ExActa: The Complement system in kidney diseases
    • Authors: S. Reuter; R. Mrowka
      Abstract: The complement system, a plasma component, was described upon its discovery to augment the opsonisation of bacteria by antibodies, ‘complementing’ said antibodies’ antibacterial activity. In its first and foremost role, the complement cascade helps convert pathogen recognition into an effective host defence. Two recent publications in Acta Physiologica have highlighted the role of complement factors in immune cell function, namely monoamine transmitter release from immune cells during immune response and inflammation1, 2This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-21T11:01:27.850864-05:
      DOI: 10.1111/apha.12909
       
  • Article submission is the true obstacle of publishing
    • Authors: P. B. Persson
      Abstract: Tempers flare as the chairman seeks rapid publication to meet grant deadlines, the assistant professor lacking tenure aims for the highest impact factor, whereas the postdoc is sick and tired of ever more rebuttals, and simply wants to end the seemingly endless rejection-resubmission-cycle.This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-16T03:55:25.895994-05:
      DOI: 10.1111/apha.12908
       
  • Cardiac heterogeneity and drug-provoked arrhythmias
    • Authors: Ursula Ravens; Christian Aalkjaer
      Abstract: Functioning of the heart as a mechanical pump depends on electrical impulse formation in the sinus node, conduction of the excitatory wave along its preformed pathways, and orderly repolarisation.This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-14T10:15:18.148281-05:
      DOI: 10.1111/apha.12907
       
  • Myoendothelial coupling through Cx40 contributes to EDH-induced
           vasodilation in murine renal arteries: Evidence from experiments and
           modelling
    • Authors: Jens Christian Brasen; Cor de Wit, Charlotte Mehlin Sorensen
      Abstract: Regulation of renal vascular resistance plays a major role in controlling arterial blood pressure. The endothelium participates in this regulation as endothelial derived hyperpolarization plays a significant role in smaller renal arteries and arterioles but the exact mechanisms are still unknownAimto investigate the role of vascular gap junctions and potassium channels in the renal endothelial derived hyperpolarization.Methodsin interlobar arteries from wild-type and connexin40 knock-out mice we assessed the role of calcium activated small (SK) and intermediate (IK) conductance potassium channels. The role of inward rectifier potassium channels (Kir) and Na+/K+-ATPases was evaluated as was the contribution from gap junctions. Mathematical models estimating diffusion of ions and electrical coupling in myoendothelial gap junctions were used to interpret the results.Resultslack of connexin40 significantly reduces renal endothelial hyperpolarization. Inhibition of SK and IK channels significantly attenuated renal EDH to a similar degree in wild-type and knock-out mice. Inhibition of Kir and Na+/K+-ATPases affected the response in wild-type and knock-out mice but at different levels of stimulation. The model confirms that activation of endothelial SK and IK channels generates a hyperpolarizing current that enters the vascular smooth muscle cells. Also, extracellular potassium increases sufficiently to activate Kir and Na+/K+-ATPases.Conclusionrenal endothelial hyperpolarization is mainly initiated by activation of IK and SK channels. The model shows that hyperpolarization can spread through myoendothelial gap junctions but enough potassium is released to activate Kir and Na+/K+-ATPases. Reduced coupling seems to shift the signaling pathway towards release of potassium. However, an alternative pathway also exists and needs to be investigated.This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-14T10:10:19.549879-05:
      DOI: 10.1111/apha.12906
       
  • Hypoxia-inducible factor-1 in myocardial ischemia/reperfusion injury
    • Authors: Francesco Bellanti
      Abstract: In this issue of Acta Physiologica, Xie et al.1 describe the protective role of hypoxia-inducible factor-1 (HIF-1) against myocardial ischemia/reperfusion injury in diabetic rats. This study demonstrates that HIF-1 signalling pathway is impaired in diabetes, abolishing the cardioprotective effect of sevoflurane post-conditioning; the administration of deferoxamine re-activates HIF-1 conferring cardioprotection.This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-05T04:18:09.918115-05:
      DOI: 10.1111/apha.12903
       
  • Exercise training increases skeletal muscle mitochondrial volume density
           by enlargement of existing mitochondria and not de novo biogenesis
    • Authors: Anne-Kristine Meinild Lundby; Robert A. Jacobs, Saskia Gehrig, Jeroen Leur, Moritz Hauser, Thomas C. Bonne, Daniela Flück, Sune Dandanell, Niels Kirk, Andreas Kaech, Urs Ziegler, Steen Larsen, Carsten Lundby
      Abstract: Aims1) determine whether exercise induced increases in muscle mitochondrial volume density (MitoVD) is related to enlargement of existing mitochondria or de novo biogenesis, 2) establish if measures of mitochondrial-specific enzymatic activities are valid biomarkers for exercise induced increases in MitoVD.MethodSkeletal muscle samples were collected from twenty-one healthy males prior to and following 6 weeks of endurance training. Transmission electron microscopy was used for estimation of mitochondrial densities and profiles. Biochemical assays, western blotting and high resolution respirometry were applied to detect changes in specific mitochondrial functions.ResultMitoVD increased with 55 ± 9% (P < 0.001), whereas the number of mitochondrial profiles per area of skeletal muscle remained unchanged following training. Citrate synthase activity (CS) increased (44 ± 12%, P < 0.001) however, there were no functional changes in oxidative phosphorylation capacity (OXPHOS, CI+IIP) or cytochrome c oxidase (COX) activity. Correlations were found between MitoVD and CS (P=0.01; r=0.58), OXPHOS, CI+CIIP (P=0.01; R=0.58) and COX (P=0.02; R=0.52) before training, after training a correlation was found between MitoVD and CS activity only (P=0.04; R=0.49). Intrinsic respiratory capacities decreased (P < 0.05) with training when respiration was normalized to MitoVD. This was not the case when normalized to CS activity although the percentage change was comparable.ConclusionsMitoVD was increased by inducing mitochondrial enlargement rather than de novo biogenesis. CS activity may be appropriate to track training induced changes in MitoVD.This article is protected by copyright. All rights reserved.
      PubDate: 2017-06-05T02:55:50.811228-05:
      DOI: 10.1111/apha.12905
       
  • Isolated pulmonary regurgitation causes decreased right ventricular
           longitudinal function and compensatory increased septal pumping in a
           porcine model
    • Authors: Sascha Kopic; Sigurdur S Stephensen, Einar Heiberg, Håkan Arheden, Philipp Bonhoeffer, Mads Ersbøll, Niels Vejlstrup, Lars Søndergaard, Marcus Carlsson
      Abstract: AimLongitudinal ventricular contraction is a parameter of cardiac performance with predictive power. Right ventricular longitudinal function is impaired in patients with free pulmonary regurgitation (PR) following corrective surgery for Tetralogy of Fallot (TOF). It remains unclear whether this is a consequence of the surgical repair, or whether it is inherent to PR. The aim of this study was to assess the relationship between longitudinal, lateral and septal pumping in a porcine model of isolated PR.MethodsPiglets were divided into a control (n=8) and a treatment (n=12) group, which received a stent in the pulmonary valve orifice, inducing PR. After two to three months animals were subjected to cardiac magnetic resonance imaging. A subset of animals (n=6) then underwent percutaneous pulmonary valve replacement (PPVR) with follow-up one month later. Longitudinal, lateral and septal contributions to stroke volume (SV) were quantified by measuring volumetric displacements from end-diastole to end-systole in the cardiac short- and long-axis.ResultsPR resulted in a lower longitudinal contribution to right ventricular (RV) stroke volume, compared to controls (60.0±2.6% vs. 73.6±3.8%; p=0.012). Furthermore, a compensatory increase in septal contribution to RVSV was observed (11.0±1.6% vs. -3.1±1.5%; p
      PubDate: 2017-06-05T02:17:36.424399-05:
      DOI: 10.1111/apha.12904
       
  • A mechanism for NaV1.5 downregulation and sodium current decrease in heart
           failure
    • Authors: Sara Pagans; Marcel Vergés
      Abstract: The pore-forming α-subunit of the cardiac voltage-gated sodium channel, NaV1.5, is responsible for the initial upstroke of the cardiac action potential. NaV1.5 cell surface expression and function are modulated by its interaction with regulatory proteins and by posttranslational modifications, such as phosphorylation, arginine methylation or ubiquitination 1. Genetic mutations in the SCN5A gene, which encodes NaV1.5, have been associated with a variety of inherited cardiac arrhythmias, including long QT syndrome type 3, Brugada syndrome, atrial fibrillation, and congenital sick sinus syndrome. In addition, abnormal NaV1.5 plasma membrane expression or sodium current (INa) density have also been observed in acquired cardiac disorders, such as heart failure (HF), although the molecular mechanisms that trigger these alterations are not well understood.This article is protected by copyright. All rights reserved.
      PubDate: 2017-05-30T07:31:06.108411-05:
      DOI: 10.1111/apha.12901
       
  • Obesity gets on your renal nerves
    • Authors: Boye L Jensen
      Abstract: In the present issue of Acta Physiologica1, Khan et al. in their article “Improvement in baroreflex control of renal sympathetic nerve activity in obese Sprague-Dawley rats following immunosuppression” confirm that obesity-related hypertension involves resetting of the arterial baroreceptor to a state of less sensitivity and relate this mechanistically to inflammation-induced altered renal afferent nerve activity 1. Pharmocological treatment with the calcineurin phosphatase inhibitor-type immunosuppressant tacrolimus attenuated inflammation, reversed, paradoxically, the hypertension and restored baroreceptor sensitivity similar to the effect of renal denervation. The paper not only points attention towards a mechanistic understanding of the baroreceptor resetting associated with chronic arterial hypertension but also demonstrates a pharmacological approach to remedy obesity-associated hypertension.This article is protected by copyright. All rights reserved.
      PubDate: 2017-05-26T06:40:25.11641-05:0
      DOI: 10.1111/apha.12900
       
  • Acute Toll-like Receptor 4 Activation Impairs Rat Renal Microvascular
           Autoregulatory Behaviour
    • Authors: Justin P. Van Beusecum; Shali Zhang, Anthony K. Cook, Edward W. Inscho
      Abstract: AimLittle is known about how toll-like receptor 4 (TLR4) influences the renal microvasculature. We hypothesized that acute TLR4 stimulation with lipopolysaccharide (LPS) impairs afferent arteriole autoregulatory behaviour, partially through reactive oxygen species (ROS).MethodsWe assessed afferent arteriole autoregulatory behaviour after LPS treatment (1 mg kg−1; i.p.) using the in vitro blood perfused juxtamedullary nephron preparation. Autoregulatory behaviour was assessed by measuring diameter responses to step-wise changes in renal perfusion pressure. TLR4 expression was assessed by immunofluorescence, immunohistochemistry and western blot analysis in the renal cortex and vasculature.ResultsBaseline arteriole diameter at 100 mmHg averaged 15.2 ± 1.2 μm and 12.2 ± 1.0 μm for control and LPS groups (P
      PubDate: 2017-05-25T09:10:49.143406-05:
      DOI: 10.1111/apha.12899
       
  • Adaptations to endurance training depend on exercise-induced oxidative
           stress: exploiting redox inter-individual variability
    • Authors: Nikos V. Margaritelis; Anastasios A. Theodorou, Vassilis Paschalis, Aristidis S. Veskoukis, Konstantina Dipla, Andreas Zafeiridis, George Panayiotou, Ioannis S. Vrabas, Antonios Kyparos, Michalis G. Nikolaidis
      Abstract: AimThe aim of the present study was to reveal the role of reactive oxygen and nitrogen species (RONS) in exercise adaptations under physiological in vivo conditions and without the interference from other exogenous redox agents (e.g., a pro-oxidant or antioxidant).MethodsWe invented a novel methodological set-up that exploited the large redox inter-individual variability in exercise responses. More specifically, we used exercise-induced oxidative stress as the “classifier” measure (i.e., low, moderate and high) and investigated the physiological and redox adaptations after a 6-wk endurance training protocol.ResultsWe demonstrated that the group with the low exercise-induced oxidative stress exhibited the lowest improvements in a battery of classic adaptations to endurance training (VO2max, time trial and Wingate test) as well as in a set of redox biomarkers (oxidative stress biomarkers and antioxidants), compared to the high and moderate oxidative stress groups.ConclusionThe findings of the present study substantiate, for the first time in a human in vivo physiological context, and in the absence of any exogenous redox manipulation, the vital role of RONS produced during exercise in adaptations. The stratification approach, based on a redox phenotype, implemented in the present study could be a useful experimental strategy to reveal the role of RONS and antioxidants in other biological manifestations as well.This article is protected by copyright. All rights reserved.
      PubDate: 2017-05-24T03:30:31.293588-05:
      DOI: 10.1111/apha.12898
       
  • Temporal overexpression of SIRT1 in skeletal muscle of adult mice does not
           improve insulin sensitivity or markers of mitochondrial biogenesis
    • Authors: Kristoffer Svensson; Samuel A. LaBarge, Vitor F. Martins, Simon Schenk
      Abstract: AimsActivation of the NAD+ dependent protein deacetylase SIRT1 has been proposed as a therapeutic strategy to treat mitochondrial dysfunction and insulin resistance in skeletal muscle. However, life-long overexpression of SIRT1 in skeletal muscle does not improve parameters of mitochondrial function and insulin sensitivity. In this study we investigated whether temporal overexpression of SIRT1 in muscle of adult mice would affect skeletal muscle mitochondrial function and insulin sensitivity.MethodsTo circumvent potential effects of germline SIRT1 overexpression, we utilized an inducible model of SIRT1 overexpression in skeletal muscle of adult mice (i-mOX). Insulin sensitivity was assessed by 2-deoxyglucose uptake, muscle maximal respiratory function by high-resolution respirometry and systemic energy expenditure was assessed by whole body calorimetry.ResultsAlthough SIRT1 was highly, and specifically, overexpressed in skeletal muscle of i-mOX compared to WT mice, glucose tolerance and skeletal muscle insulin sensitivity were comparable between genotypes. Additionally, markers of mitochondrial biogenesis, muscle maximal respiratory function and whole body oxygen consumption were also unaffected by SIRT1 overexpression.ConclusionThese results support previous work demonstrating that induction of SIRT1 in skeletal muscle, either at birth or in adulthood, does not impact muscle insulin action or mitochondrial function.This article is protected by copyright. All rights reserved.
      PubDate: 2017-05-22T12:31:09.254751-05:
      DOI: 10.1111/apha.12897
       
  • Microparticles of healthy origins improve endothelial progenitor cell
           dysfunction via microRNA transfer in an atherosclerotic hamster model
    • Authors: Nicoleta Alexandru; Eugen Andrei, Loredan Niculescu, Emanuel Dragan, Violeta Ristoiu, Adriana Georgescu
      Abstract: AimIn this study we aimed: (1) to obtain and functionally characterize the cultures of late endothelial progenitor cells (EPCs) from the animal blood; (2) to investigate the potential beneficial effects of circulating microparticles (MPs) of healthy origins on EPC dysfunctionality in atherosclerosis as well as involved mechanisms.MethodsLate EPCs were obtained and expanded in culture from peripheral blood isolated from two animal groups: hypertensive-hyperlipidemic (HH) and control (C) hamsters. In parallel experiments, late EPC cultures from HH were incubated with MPs from C group.ResultsThe results showed that late EPCs display endothelial cell phenotype: (1) have ability to uptake Dil-Ac-LDL and UEA-1; (2) express CD34, CD133, KDR, CD144, vWF, Tie-2. Late EPCs from HH exhibited different morphological and functional characteristics compared to control: (1) are smaller and irregular in shape; (2) present decreased endothelial surface marker expression; (3) display reduced proliferation, migration and adhesion; (4) lose ability to organize themselves into tubular structures and integrate into vascular network; (5) have diminished function of inward rectifier potassium channels. The incubation of late EPCs with MPs improved EPC functionality by miR-10a, miR-21, miR-126, miR-146a, miR-223 transfer and IGF-1 expression activation; the kinetic study of MP incorporation into EPCs demonstrated MP uptake by EPCs followed by the miRNA transfer.ConclusionThe data reveal that late EPCs from atherosclerotic model exhibit distinctive features and are dysfunctional, and their function recovery can be supported by MP ability to transfer miRNAs. These findings bring a new light on the vascular repair in atherosclerosis.This article is protected by copyright. All rights reserved.
      PubDate: 2017-05-17T09:25:34.275274-05:
      DOI: 10.1111/apha.12896
       
  • Isopimaric acid – a multi-targeting ion channel modulator reducing
           excitability and arrhythmicity in a spontaneously beating mouse atrial
           cell line
    • Authors: Sajjad Salari; Malin Silverå Ejneby, Johan Brask, Fredrik Elinder
      Abstract: AimAtrial fibrillation is the most common persistent cardiac arrhythmia, and it is not well controlled by present drugs. Because some resin acids open voltage-gated potassium channels and reduce neuronal excitability, we explored the effects of the resin acid isopimaric acid (IPA) on action potentials and ion currents in cardiomyocytes.MethodsSpontaneously beating mouse atrial HL-1 cells were investigated with the whole-cell patch-clamp technique.Results1-25 μmol L‒1 IPA reduced the action potential frequency by up to 50%. The effect of IPA on six different voltage-gated ion channels was investigated; most voltage-dependent parameters of ion-channel gating were shifted in the negative direction along the voltage axis, consistent with an hypothesis that a lipophilic and negatively charged compound binds to the lipid membrane close to the positively charged voltage sensor of the ion channels. The major finding was that IPA inactivated sodium channels and L- and T-type calcium channels, and activated the rapidly activating potassium channel and the transient outward potassium channel. Computer simulations of IPA effects on all of the ion currents were consistent with a reduced excitability, and they also showed that effects on the Na channel played the largest role to reduce the action potential frequency. Finally, induced arrhythmia in the HL-1 cells was reversed by IPA.ConclusionLow concentrations of IPA reduced the action potential frequency and restored regular firing by altering the voltage dependencies of several voltage-gated ion channels. These findings can form the basis for a new pharmacological strategy to treat atrial fibrillation.This article is protected by copyright. All rights reserved.
      PubDate: 2017-05-17T09:20:37.453343-05:
      DOI: 10.1111/apha.12895
       
  • Altitude sickness and altitude adaptation
    • Authors: Pontus B. Persson; Anja B. Persson
      Abstract: For as long as humanity can recall, it has probably been a dream of mankind to conquer mountainous heights and the mysterious deep. Loss of innocence is a common theme across ancient religions. Ancient Hindu legend has an interesting variation on the story: When Brahma realized that man did not deserve divinity, he decided to take it from them and hide it, but where' Brahma did what researchers up to present day are familiar with: ask your peers, in his case, a board of other gods. Brainstorming yielded a number of potential hiding places.This article is protected by copyright. All rights reserved.
      PubDate: 2017-05-12T10:56:00.304823-05:
      DOI: 10.1111/apha.12894
       
  • Age-related endothelial dysfunction in human skeletal muscle feed
           arteries: The role of free radicals derived from mitochondria in the
           vasculature
    • Authors: Song-Young Park; Oh Sung Kwon, Robert H. I. Andtbacka, John R. Hyngstrom, Van Reese, Michael P. Murphy, Russell S. Richardson
      Abstract: AimThis study sought to determine the role of free radicals derived from mitochondria in the vasculature in the recognized age-related endothelial dysfunction of human skeletal muscle feed arteries (SMFAs).MethodsA total of 44 SMFAs were studied with and without acute exposure to the mitochondria-targeted antioxidant MitoQ and nitric oxide synthase (NOS) blockade. The relative abundance of proteins from the electron transport chain, phosphorylated (p-) to endothelial (e) NOS ratio, manganese superoxide dismutase (MnSOD), and the mitochondria-derived superoxide (O2-) levels were assessed in SMFA. Endothelium-dependent and -independent SMFA vasodilation was assessed in response to flow-induced shear stress, acetylcholine (ACh), and sodium nitroprusside (SNP).ResultsMitoQ restored endothelium-dependent vasodilation in the old to that of the young when stimulated by both flow (Young: 68±5; Old: 25±7; Old+MitoQ 65±9%) and ACh (Young: 97±4; Old: 59±10; Old+MitoQ: 98±5%), but did not alter, the initially uncompromised, endothelium-independent vasodilation (SNP). Compared to the young, MitoQ in the old diminished the initially elevated mitochondria-derived O2- levels and appeared to attenuate the breakdown of MnSOD. Furthermore, MitoQ increased the ratio of p-eNOS/NOS and the restoration of endothelium-dependent vasodilation in the old by MitoQ was ablated by NOS blockade.ConclusionThis study demonstrated that MitoQ reverses age-related vascular dysfunction by what appears to be an NO-dependent mechanism in human SMFAs. These findings suggest that mitochondrial-targeted antioxidants may have utility in terms of counteracting the attenuated blood flow and vascular dysfunction associated with advancing age.This article is protected by copyright. All rights reserved.
      PubDate: 2017-05-11T10:05:32.235067-05:
      DOI: 10.1111/apha.12893
       
  • Neurological and Neuropsychological Effects of Low and Moderate Prenatal
           Alcohol Exposure
    • Authors: Erika Comasco; Jenny Rangmar, Ulf J. Eriksson, Lars Oreland
      Abstract: Several explanations for the diverse results in research on Foetal Alcohol Spectrum Disorders (FASD) or Alcohol-Related Neuro-developmental Disorder (ARND) might be at hand: timing, amount and patterns of alcohol exposure, as well as complex epigenetic responses. The genetic background of the offspring and its interaction with other prenatal and postnatal environmental cues are likely also of importance. In the present report, key findings about the possible effects of low and moderate doses of maternal alcohol intake on the neuropsychological development of the offspring are reviewed and plausible mechanisms discussed. Special focus is put on the serotonergic system within developmental and gene-environment frameworks. The review also suggests guidelines for future studies, as well as summarises some of to be-answered questions of relevance to clinical practice.Contradictory findings and paucity of studies on the effects of exposure to low alcohol levels during foetal life for the offspring's neuropsychological development call for large prospective studies, as well as for studies including neuroimaging and multi-omics analyses to dissect the neurobiological underpinnings of alcohol exposure-related phenotypes and to identify biomarkers. Finally, it remains to be investigated whether any safe threshold of alcohol drinking during pregnancy can be identified.This article is protected by copyright. All rights reserved.
      PubDate: 2017-05-04T03:00:28.570201-05:
      DOI: 10.1111/apha.12892
       
  • Improvement in baroreflex control of renal sympathetic nerve activity in
           obese Sprague-Dawley rats following immunosuppression
    • Authors: Safia Akhtar Khan; Munavvar Zubaid Abdul Sattar, Nor Azizan Abdullah, Hassaan Anwer Rathore, Ashfaq Ahmad, Mohammed Hadi Abdulla, Edward James Johns
      Abstract: AimThis investigation explored the hypothesis that in obesity an inflammatory response in the kidney contributed to a renal nerve-dependent blunting of the baroreflex regulation of renal sympathetic nerve activity.MethodsRats received a normal (12%Kcal) or high-fat (45%Kcal) diet for 8 weeks plus daily injections of vehicle (0.9% NaCl i.p) or tacrolimus (0.25mg kg−1day−1i.p) from weeks 3-8. Following anaesthesia, left renal sympathetic nerve activity was recorded, baroreflex gain curves were generated, by infusing phenylephrine and sodium nitroprusside, and cardiopulmonary baroreceptors challenged by infusing a saline load.ResultsThe high-fat diet elevated weight gain and adiposity index by 89 and 129% (both, P
      PubDate: 2017-04-29T04:59:42.379893-05:
      DOI: 10.1111/apha.12891
       
  • Inhibitory action of oxytocin on spontaneous contraction of rat distal
           colon by nitrergic mechanism: involvement of cyclic GMP and
           apamin-sensitive K+ channels
    • Authors: R Wang; MT Han, XL LV, YA Yu, SQ Chai, CM Qu, CY Liu
      Abstract: AimThe mechanisms underlying the inhibitory effects of oxytocin (OT) on colon tone are not totally understood. We explore the mechanisms of OT on spontaneous contractility in rat distal colon, and identify the mediators involved in this action.MethodsIn rat distal colon strips, mechanical activity was analyzed and the production of nitric oxide (NO) in tissue loaded with the fluorochrome DAF-FM was visualized by confocal microscopy. OT receptor (OTR) expression was determined by western blotting and immunofluorescence.ResultsIn rat distal colon, OT produced a concentration-dependent reduction of the spontaneous contraction, which was abolished by the OTR antagonist atosiban, the neural blocker tetrodotoxin and the inhibitor of neuronal nitric oxide synthase (nNOS) NPLA. The inhibitory effects of OT were not affected by propranolol, atropine, the nicotinic cholinoceptor blocker hexamethonium, the vasoactive intestinal peptide receptor antagonist VIPHyb, the P2 purinoceptor antagonist PPADS, the adenosine A1 receptors antagonist DPCPX and the prostacyclin receptor antagonist Ro1138452. The soluble guanylyl cyclase (sGC) inhibitor ODQ and the small conductance Ca2+-activated K+ (CaK+) channels blocker apamin significantly reduced the relaxation induced by OT, nicotine, sodium nitroprusside and the sGC activator BAY 41-2272. The neural release of NO elicited by OT was prevented by NPLA, tetrodotoxin, and atosiban. The presence of the OTR and its co-localization with nNOS was detected by immunohistochemistry and western blotting experiments.ConclusionThese results demonstrate the NO release from enteric neurons induced by activation of OTR mediates distal colon relaxation. sGC and small conductance CaK+ channels are involved in this relaxation.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-26T10:30:44.519742-05:
      DOI: 10.1111/apha.12890
       
  • Membrane traffic control by hypoxia
    • Authors: Joachim Fandrey
      Abstract: Cells and tissues have to adapt to adverse changes in their environment to survive and continue to function. The lack of oxygen, hypoxia, is one of the fundamental challenges to which cells need to respond in a coordinate manner. In this issue of Acta Physiologica Wottawa et al.1 studied hypoxia induced membrane trafficking.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-26T10:25:34.997485-05:
      DOI: 10.1111/apha.12889
       
  • In defence of pH
    • Authors: Holger Nilsson
      Abstract: The maintenance of the milieu intérieur is at an essential concept in physiology. The first line of defence against perturbations of the internal environment consists of the homeostatic mechanisms that maintain constancy of the extracellular fluid. A second line of defence is the maintenance of a constant intracellular environment, should the extracellular have been compromised. In this issue of Acta Physiologica, Bonde and Boedtkjer1 study the maintenance of intracellular pH under situations of increased acidity and reduced sodium concentration in the extracellular environment.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-21T04:15:41.789768-05:
      DOI: 10.1111/apha.12888
       
  • CO2 Permeability and Carbonic Anhydrase Activity of Rat Cardiomyocytes
    • Authors: Mariela Arias-Hidalgo; Samer Al-Samir, Natalie Weber, Cornelia Geers-Knörr, Gerolf Gros, Volker Endeward
      Abstract: AimWe determine here the CO2 permeability (PCO2) of plasma membranes of cardiomyocytes. These cells were chosen because heart possesses the highest rate of O2-consumption/CO2-production in the body.MethodsCardiomyocytes were isolated from rat hearts using the Langendorff technique. Cardiomyocyte suspensions exhibited a vitality of 2-14% and were studied by the previously described mass spectrometric 18O-exchange-technique deriving PCO2. We show by mass spectrometry and by carbonic anhydrase (CA)-staining that non-vital cardiomyocytes are free of CA and thus do not contribute to the mass spectrometric signal, which is determined exclusively by the fully functional vital cardiomyocytes.ResultsLysed cardiomyocytes yield an intracellular CA-activity for vital cells of 5,070, i.e. the rate of CO2 hydration inside the cell is accelerated 5,071-fold. Using this number, analyses of the mass spectrometric recordings from cardiomyocyte suspensions yield a PCO2 of 0.10 cm∙s−1 (SD±0.06, n =15) at 37°C.ConclusionsIn comparison to the PCO2 of other cells, this value is quite high and about identical to that of the human red cell membrane. Since no major protein CO2-channels such as aquaporin-1 and 4 are present in rat cardiac sarcolemma, the high PCO2 of this membrane is likely due to its low cholesterol content of about 0.2 mol cholesterol ∙ (mol total membrane lipids)−1. Previous work predicts a PCO2 of ≥ 0.1 cm∙s−1 from this level of cholesterol. We conclude that the low cholesterol establishes a PCO2 high enough to render the membrane resistance to CO2 diffusion almost negligible, even under conditions of maximal O2 consumption of the heart.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-20T21:23:23.221718-05:
      DOI: 10.1111/apha.12887
       
  • Weak by the Machines: Muscle Motor Protein Dysfunction -NDASH- a side
           Effect of Intensive Care Unit Treatment
    • Authors: O Friedrich; S Diermeier, L Larsson
      Abstract: Intensive care interventions involve periods of mechanical ventilation, sedation and complete mechanical silencing of patients. Critical illness myopathy (CIM) is an ICU-acquired myopathy that is associated with limb muscle weakness, muscle atrophy, electrical silencing of muscle and motor-proteinopathy. The hallmark of CIM is a preferential muscle myosin loss due to increased catabolic and reduced anabolic activity. The ubiquitin-proteasome pathway plays an important role, apart from recently identified novel mechanisms affecting nonlysosomal protein degradation or autophagy. CIM is not reproduced by pure disuse atrophy, denervation atrophy, steroid-induced atrophy or septic myopathy, although combinations of high-dose steroids and denervation can mimic CIM. Novel animal models of critical illness and ICU-treatment (i.e. mechanical ventilation and complete immobilization) provide novel insights regarding the time course of protein synthesis and degradation alterations, and the role of protective chaperone activities in the process of myosin loss. Altered mechano-signaling seems involved in triggering a major part of myosin loss in experimental CIM models and passive loading of muscle potently ameliorates the CIM phenotype. We provide a systematic overview of similarities and distinct differences in the signaling pathways involved in triggering muscle atrophy in CIM and isolated trigger factors. Since preferential myosin loss is mostly determined from biochemistry analyses providing no spatial resolution of myosin loss processes within myofibres, we also provide first results monitoring myosin signal intensities during experimental ICU-intervention using multiphoton Second harmonic Generation microscopy. Our results confirm that myosin loss is an evenly distributed process within myofibres rather than being confined to hot spots.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-07T02:37:01.268769-05:
      DOI: 10.1111/apha.12885
       
  • The role of neuropeptide W in energy homeostasis
    • Authors: Hui Li; Stephen J Kentish, Gary A Wittert, Amanda J Page
      Abstract: Neuropeptide W is the endogenous ligand for G-protein-coupled receptors GPR7 and GPR8. In this review, we summarize findings on the distribution of neuropeptide W and its receptors in the central nervous system and the periphery, and discuss the role of NPW in food intake and energy homeostasis.This article is protected by copyright. All rights reserved.
      PubDate: 2017-04-04T15:05:24.623783-05:
      DOI: 10.1111/apha.12884
       
  • Transcriptional regulation of voltage-gated Ca2+ channels
    • Authors: Ricardo González-Ramírez; Ricardo Felix
      Abstract: The transcriptional regulation of voltage-gated Ca2+ (CaV) channels is an emerging research area that promises to improve our understanding of how many relevant physiological events are shaped in the central nervous system, the skeletal muscle, and other tissues. Interestingly, a picture of how transcription of CaV channel subunit genes is controlled is evolving with the identification of the promoter regions required for tissue-specific expression, and the identification of transcription factors that control their expression. These promoters share several characteristics that include multiple transcriptional start sites, lack of a TATA box, and the presence of elements conferring tissue-selective expression. Likewise, changes in CaV channel expression occur throughout development, following ischemia, seizures, or chronic drug administration. This review focuses on insights achieved regarding the control of CaV channel gene expression. To further understand the complexities of expression and to increase the possibilities of detecting CaV channel alterations causing human disease, a deeper knowledge on the structure of the 5’ upstream regions of the genes encoding these remarkable proteins will be necessary.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-31T18:40:23.72669-05:0
      DOI: 10.1111/apha.12883
       
  • Exercise and epigenetic inheritance of disease risk
    • Authors: Joshua Denham
      Abstract: Epigenetics is the study of gene expression changes that occur in the absence of altered genotype. Current evidence indicates a role for environmentally induced alterations to epigenetic modifications leading to health and diseases changes across multiple generations. This phenomenon is called intergenerational or transgenerational epigenetic inheritance of health or disease.Environmental insults, in the form of toxins, plastics and particular dietary interventions, perturb the epigenetic landscape and influence the health of F1 through to F4 generations in rodents. There is, however, the possibility that healthy lifestyles and environmental factors, such as exercise training, could lead to favourable, heritable epigenetic modifications that augment transcriptional programs protective of disease, including metabolic dysfunction, heart disease and cancer. The health benefits conferred by regular physical exercise training are unquestionable, yet many of the molecular changes may have heritable health implications for future generations. Similar to other environmental factors, exercise modulates the epigenome of somatic cells and researchers are beginning to study exercise epigenetics in germ cells. The germ cell epigenetic modifications affected by exercise offer a molecular mechanism for the inheritance of health and disease risk.The aims of this review are to: 1) provide an update on the expanding field of exercise epigenetics; 2) offer an overview of data on intergenerational/transgenerational epigenetic inheritance of disease by environmental insults; 3) to discuss the potential of exercise-induced intergenerational inheritance of health and disease risk; and finally, outline potential mechanisms and avenues for future work on epigenetic inheritance through exercise.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-30T06:16:01.520992-05:
      DOI: 10.1111/apha.12881
       
  • Role of renal vascular potassium channels in physiology and
           pathophysiology
    • Authors: Max Salomonsson; Jens Christian Brasen, Charlotte M. Sorensen
      Abstract: The control of renal vascular tone is important for the regulation of salt and water balance, blood pressure and the protection against damaging elevated glomerular pressure. The K+ conductance is a major factor in the regulation of the membrane potential (Vm) in vascular smooth muscle (VSMC) and endothelial cells (EC). The vascular tone is controlled by Vm via its effect on the opening probability of voltage operated Ca2+channels (VOCC) in VSMC. When K+ conductance increases Vm becomes more negative and vasodilation follows, while deactivation of K+ channels leads to depolarization and vasoconstriction. K+ channels in EC indirectly participate in the control of vascular tone by endothelium derived vasodilation. Therefore, by regulating the tone of renal resistance vessels, K+ channels have a potential role in the control of fluid homeostasis and blood pressure as well as in the protection of the renal parenchyma. The main classes of K+ channels (calcium activated (KCa), inward rectifier (Kir), voltage activated (Kv) and ATP sensitive (KATP)) have been found in the renal vessels. In this review, we summarize results available in the literature and our own studies in the field. We compare the ambiguous in vitro and in vivo results. We discuss the role of single types of K+ channels and the integrated function of several classes. We also deal with the possible role of renal vascular K+ channels in the pathophysiology of hypertension, diabetes mellitus and sepsis.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-30T06:05:35.478948-05:
      DOI: 10.1111/apha.12882
       
  • Cortical adaptations during muscle fatigue: the role of sensorimotor
           oscillations
    • Authors: Tjeerd W. Boonstra
      Abstract: During physical activity, fatigue arises not only from peripheral processes within the active spinal motor units but also from supraspinal mechanisms within the brain. Although the failure to generate a maximal output from the motor cortex is well established, the neural mechanisms of central fatigue remain unclear. In a recent study, Fry et al. 1 investigate changes in oscillatory activity in sensorimotor cortex following a fatiguing intervention to identify the cortical adaptations to muscle fatigue.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-29T21:40:23.934807-05:
      DOI: 10.1111/apha.12879
       
  • Modeling vision: computational science for understanding human visual
           perception
    • Authors: Ralf Mrowka; Alexander Freytag, Stefanie Reuter
      Abstract: Human visual perception system is complex and involves a considerable portion of the brain's cortex. Hence, the wish to understand complex neuronal function is obvious, and the idea to model this by means of artificial neuronal networks might have been born at the time when first computational machines were constructed (Alan Turing, Intelligent machinery, 1948, h t t p: //www.npl.co.uk/about/history/notable-individuals/turing/intelligent-machinery)This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-25T00:07:32.619018-05:
      DOI: 10.1111/apha.12875
       
  • Extracellular acidosis and very low [Na+] inhibit NBCn1- and NHE1-mediated
           net acid extrusion from mouse vascular smooth muscle cells
    • Authors: Lisbeth Bonde; Ebbe Boedtkjer
      Abstract: AimThe electroneutral Na+,HCO3–-cotransporter NBCn1 and Na+/H+-exchanger NHE1 regulate acid-base balance in vascular smooth muscle cells (VSMCs) and modify artery function and structure. Pathological conditions—notably ischemia—can dramatically perturb intracellular (i) and extracellular (o) pH and [Na+]. We examined effects of low [Na+]o and pHo on NBCn1 and NHE1 activity in VSMCs of small arteries.MethodsWe measured pHi by 2’,7’-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein-based fluorescence microscopy of mouse mesenteric arteries and induced intracellular acidification by NH4+-prepulse technique.ResultsNBCn1 activity—defined as Na+-dependent, amiloride-insensitive net base uptake with CO2/HCO3– present—was inhibited equally when pHo decreased from 7.4 (22 mM HCO3–/5% CO2) by metabolic (pHo 7.1/11 mM HCO3–: 22±8%; pHo 6.8/5.5 mM HCO3–: 61±7%) or respiratory (pHo 7.1/10% CO2: 35±11%; pHo 6.8/20% CO2: 56±7%) acidosis. Extracellular acidosis more prominently inhibited NHE1 activity—defined as Na+-dependent net acid extrusion without CO2/HCO3– present—at both pHo 7.1 (45±9%) and 6.8 (85±5%). Independently of pHo, lowering [Na+]o from 140 to 70 mM reduced NBCn1 and NHE1 activity less than 20% whereas transport activities declined markedly (25-50%) when [Na+]o was reduced to 35 mM. Steady-state pHi decreased more during respiratory (ΔpHi/ΔpHo=71±4%) than metabolic (ΔpHi/ΔpHo=30±7%) acidosis.ConclusionExtracellular acidification inhibits NBCn1 and NHE1 activity in VSMCs. NBCn1 is equivalently inhibited when pCO2 is raised or [HCO3–]o decreased. Lowering [Na+]o inhibits NBCn1 and NHE1 markedly only below the typical physiological and pathophysiological range. We propose that inhibition of Na+-dependent net acid extrusion at low pHo protects against cellular Na+ overload at the cost of intracellular acidification.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-20T08:30:42.126164-05:
      DOI: 10.1111/apha.12877
       
  • Release of calcium into the myofibrillar space in response to active
           shortening of striated muscle
    • Authors: K.A.P. Edman; C. Caputo
      Abstract: AimThe study was undertaken to explore whether shortening of striated muscle during activity is associated with release of bound Ca2+ into the myofibrillar space as has previously been proposed in order to explain the depressant effect of active shortening.MethodsThe experiments were carried out on single muscle fibres isolated from the anterior tibialis muscle of Rana temporaria. The fibres were loaded with the calcium sensitive indicator Fluo-3. The fibres, stimulated to produce a partially fused isometric tetanus, were subjected to a shortening ramp or, alternatively, to a stretch ramp during activity while force, fibre length, sarcomere length and the Fluo-3 signal were recorded.ResultsA shortening ramp performed during a partially fused tetanus caused an increase in the myofibrillar free calcium concentration and produced, simultaneously, a decrease in active force. The isometric force recovered gradually after the shortening ramp while the intracellular Ca2+ concentration stayed above the control level during the remainder of the stimulation period. A stretch ramp applied during a partially fused tetanus caused a considerably smaller change in the myofibrillar Ca2+ concentration.ConclusionThe results provide evidence that the myosin cross-bridges interact with the calcium binding sites on the thin filaments during active shortening, causing sustained release of calcium and reduced contractile strength.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-19T20:16:06.231363-05:
      DOI: 10.1111/apha.12876
       
  • Deferoxamine-activated hypoxia-inducible factor-1 restores
           
    • Authors: Peng Xie; Long Yang, Ailaiti Talaiti, Jianjiang Wu, Jin Yu, Tian Yu, Haiying Wang, Bo Huang, Qin Wu, Yiliyaer Maimaitili, Jiang Wang, Haiping Ma, Yining Yang, Hong Zheng
      Abstract: AimThe cardioprotective effects of sevoflurane postconditioning (SpostC) are eliminated under diabetic conditions, and the underlying mechanism for this phenomenon remains unclear. Many studies have demonstrated that the hypoxia-inducible factor-1(HIF-1) signaling pathway in the myocardium is impaired under diabetic conditions. This study was to investigate whether deferoxamine (DFO)-induced activation of HIF-1 signaling pathway can restore the cardioprotective effects of SpostC in diabetic rats.MethodsA model of myocardial ischemia/reperfusion (I/R) injury was induced via ligation of the left anterior descending artery. SpostC was conducted by administering 1.0 MAC sevoflurane. After inducing the I/R injury, the following parameters were measured: myocardial infarct size, cardiac function, myocardial ultrastructure, mitochondrial respiratory function, respiratory chain enzyme activity, rate of reactive oxygen species (ROS) generation, and protein expression of HIF-1α, vascular endothelial growth factor (VEGF), cleaved caspase-3, Bcl-2 and Bax.ResultsAfter DFO activated HIF-1 in the impaired myocardium of diabetic rats, SpostC significantly upregulated the protein expression of HIF-1α and its downstream mediator VEGF. This improved myocardial mitochondrial respiratory function and respiratory chain enzyme activity and reduced ROS generation as well as the protein expression of cleaved caspase-3 and Bax. As a result, myocardial infarct size decreased, and cardiac function and mitochondrial ultrastructure improved.ConclusionThis study demonstrates for the first time that abolishment of the cardioprotective effects of SpostC in diabetic rats is associated with impairment of the HIF-1 signaling pathway, and that DFO can activate HIF-1 to restore these cardioprotective effects of SpostC in diabetic rats.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-17T18:05:50.17359-05:0
      DOI: 10.1111/apha.12874
       
  • Chronically elevated bilirubin protects from cardiac reperfusion injury in
           the male Gunn rat
    • Authors: B. Bakrania; E. F. Du Toit, K. J. Ashton, K-H. Wagner, J. P. Headrick, A. C. Bulmer
      Abstract: AimsBilirubin is associated with reduced risk of cardiovascular disease, as evidenced in conditions of mild hyperbilirubinaemia (Gilbert's Syndrome). Little is known regarding myocardial stress resistance in hyperbilirubinaemic conditions or whether life-long exposure modifies cardiac function, which might contribute to protection from cardiovascular disease.MethodsHyperbilirubinaemic rats and littermate controls underwent echocardiography at 3, 6 and 12 months of age, with hearts subsequently assessed for resistance to 30 min of ischaemia. Heart tissue was then collected for assessment of bilirubin content.ResultsNo difference in baseline cardiac function was evident until 6 months onwards, where Gunn rats demonstrated aortic dilatation and reduced peak ejection velocities. Additionally, duration of ventricular ejection increased progressively, indicating a negative inotropic effect of bilirubin in vivo. Ex vivo analysis of baseline function revealed reduced left ventricular pressure development (LVDP) and contractility in hyperbilirubinaemic rats. Furthermore, stress resistance was improved in Gunn hearts: post-ischaemic recoveries of LVDP (76 ± 22% vs. 29 ± 17% Control, P < 0.01) and coronary flow (96 ± 9% vs. 86 ± 16% Control, P < 0.01) were improved in Gunn hearts, accompanied by reduced infarct area (21 ± 5% vs. 47 ± 15% Control, P < 0.01), and ventricular malondialdehyde and protein carbonyl content. Expression of myocardial nitric oxide-regulating genes including Nos1 and Noa1 were not significantly different.ConclusionsThese data reveal life-long hyperbilirubinaemia induces age-dependent hypocontractility in male Gunn rats, and improved stress resistance. In addition, bilirubin exerts sex-independent effects on vascular structure, myocardial function and ischaemic tolerance, the latter likely mediated via bilirubin's antioxidant properties.
      PubDate: 2017-03-14T04:50:33.08502-05:0
      DOI: 10.1111/apha.12858
       
  • Bilirubin protects the aging heart
    • Authors: Samuel O. Adeosun; David E. Stec
      Abstract: In this issue of Acta Physiologica, Bakrania, et al., examined the effects of hyperbilirubinemia on the aging male heart under basal conditions and after ischemic injury 1. Heart disease is a significant problem for the aging population in general and males in particular. Ischemic heart disease is a leading cause of global mortality for males and is responsible for one out of four deaths in males in the United States. Therefore, developing novel strategies to combat the development and progression of heart disease has the potential to save millions of lives a year. Bilirubin is a metabolite generated by the breakdown of heme by heme oxygenase enzymes. Plasma levels of unconjugated bilirubin are elevated when its conjugation in the liver by UDP-glucuronosyltransferase 1-1 (UGT1A1) is altered as is observed in conditions such as Gilbert's syndrome. Several studies have linked increased levels of plasma bilirubin with a lower incidence of heart disease both in population studies as well as in patients with Gilbert's syndrome 2, 3. Although the correlative data linking alterations in plasma bilirubin levels with the development of heart disease is very convincing, the direct effects of bilirubin on cardiac function are not as established.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-10T11:05:37.152475-05:
      DOI: 10.1111/apha.12873
       
  • Calcium-dependent Nedd4-2 upregulation mediates degradation of the cardiac
           sodium channel Nav1.5: implications for heart failure
    • Authors: Ling Luo; Feifei Ning, Yuan Du, Bingxue Song, Dandan Yang, Samantha C. Salvage, Ya Wang, James A. Fraser, Shetuan Zhang, Aiqun Ma, Tingzhong Wang
      Abstract: AimReductions of voltage-gated sodium channel (Nav1.5) function/expression provide a slowed-conduction substrate for cardiac arrhythmias. Nedd4-2, which is activated by calcium, post-translationally modulates Nav1.5. We aim to investigate whether elevated intracellular calcium ([Ca2+]i) reduces Nav1.5 through Nedd4-2 and its role in heart failure (HF).MethodsUsing a combination of biochemical, electrophysiological, cellular and in vivo methods, we tested the effect and mechanism of calcium on Nedd4-2 and in turn Nav1.5.ResultsIncreased [Ca2+]i, following 24-hour ionomycin treatment, decreased sodium current (INa) density and Nav1.5 protein without altering its mRNA in both neonatal rat cardiomyocytes (NRCMs) and HEK 293 cells stably expressing Nav1.5. The calcium chelator BAPTA-AM restored the reduced Nav1.5 and INa in NRCMs pretreated by ionomycin. Nav1.5 was decreased by Nedd4-2 transfection and further decreased by 6-hour ionomycin treatment. These effects were not observed in cells transfected with the catalytically inactive mutant, Nedd4-2 C801S or with Y1977A- Nav1.5 mutant containing the impaired Nedd4-2 binding motif. Furthermore, elevated [Ca2+]i increased Nedd4-2, the interaction between Nedd4-2 and Nav1.5, and Nav1.5 ubiquitination. Nav1.5 protein is decreased whereas Nedd4-2 is increased in volume-overload HF rat hearts, with increased co-localization of Nav1.5 with ubiquitin or Nedd4-2 as indicated by immunofluorescence staining. BAPTA-AM rescued the reduced Nav1.5 protein, INa and increased Nedd4-2 in hypertrophied NRCMs induced by isoproterenol or angiotensin II.ConclusionCalcium-mediated increases of Nedd4-2 downregulates Nav1.5 by ubiquitination. Nav1.5 is downregulated and co-localizes with Nedd4-2 and ubiquitin in failing rat heart. These data suggest a role of Nedd4-2 in Nav1.5 downregulation in HF.This article is protected by copyright. All rights reserved.
      PubDate: 2017-03-10T11:04:50.308165-05:
      DOI: 10.1111/apha.12872
       
  • The innervation of the kidney in renal injury and inflammation: a cause
           and consequence of deranged cardiovascular control
    • Authors: M. H. Abdulla; E. J. Johns
      Abstract: Extensive investigations have revealed that renal sympathetic nerves regulate renin secretion, tubular fluid reabsorption and renal haemodynamics which can impact on cardiovascular homoeostasis normally and in pathophysiological states. The significance of the renal afferent innervation and its role in determining the autonomic control of the cardiovascular system is uncertain. The transduction pathways at the renal afferent nerves have been shown to require pro-inflammatory mediators and TRPV1 channels. Reno-renal reflexes have been described, both inhibitory and excitatory, demonstrating that a neural link exists between kidneys and may determine the distribution of excretory and haemodynamic function between the two kidneys. The impact of renal afferent nerve activity on basal and reflex regulation of global sympathetic drive remains opaque. There is clinical and experimental evidence that in states of chronic kidney disease and renal injury, there is infiltration of T-helper cells with a sympatho-excitation and blunting of the high- and low-pressure baroreceptor reflexes regulating renal sympathetic nerve activity. The baroreceptor deficits are renal nerve-dependent as the dysregulation can be relieved by renal denervation. There is also experimental evidence that in obese states, there is a sympatho-excitation and disrupted baroreflex regulation of renal sympathetic nerve activity which is mediated by the renal innervation. This body of information provides an important basis for directing greater attention to the role of renal injury/inflammation causing an inappropriate activation of the renal afferent nerves as an important initiator of aberrant autonomic cardiovascular control.
      PubDate: 2017-03-09T04:15:36.921535-05:
      DOI: 10.1111/apha.12856
       
  • Muscle oxygen saturation increases during head-up tilt induced
           (pre)syncope
    • Authors: A. Lund; H. Sørensen, T.W. Jensen, M.J. Niemann, N.D. Olesen, H.B. Nielsen, N.V. Olsen, N.H. Secher
      Abstract: AimTo evaluate whether muscle vasodilatation plays a role for hypotension developed during central hypovolaemia, muscle oxygenation (SmO2) was examined during (pre)syncope induced by head-up tilt (HUT). Skin blood flow (SkBF) and oxygenation (SskinO2) were determined because evaluation of SmO2 may be affected by superficial tissue oxygenation. Furthermore, we evaluated cerebral oxygenation (ScO2) and middle cerebral artery mean blood flow velocity (MCAvmean).MethodsTwenty healthy male volunteers (median age 24 years; range 19-38) were subjected to passive 50° HUT for 1 hour or until (pre)syncope. ScO2 and SmO2 (near infrared spectroscopy), MCAvmean (transcranial Doppler) along with mean arterial pressure (MAP), heart rate (HR), stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR) (Modelflow®) were determined.Results(Pre)syncopal symptoms appeared in 17 subjects after 11 min (median; range 2-34) accompanied by a decrease in MAP, SV, CO, and TPR, while HR remained elevated. During (pre)syncope, ScO2 decreased (73% (71-76; mean and 95% CI) to 68% (65-71), p
      PubDate: 2017-03-06T02:30:32.669061-05:
      DOI: 10.1111/apha.12863
       
  • Vagal nerve stimulation reduces infarct size via a mechanism involving the
           alpha-7 nicotinic acetylcholine receptor and down-regulation of cardiac
           and vascular arginase
    • Authors: Attila Kiss; Yahor Tratsiakovich, Ali Mahdi, Jiangning Yang, Adrian T Gonon, Bruno K Podesser, John Pernow
      Abstract: AimsVagal nerve stimulation (VNS) protects from myocardial and vascular injury following myocardial ischemia and reperfusion (IR) via a mechanism involving activation of alpha-7 nicotinic acetylcholine receptor (α7 nAChR) and reduced inflammation. Arginase is involved in development of myocardial IR injury driven by inflammatory mediators. The aim of the study was to clarify whether VNS downregulates myocardial and vascular arginase via a mechanism involving activation of α7 nAChR following myocardial IRMethodsAnaesthetized rats were randomized to (1) sham operated, (2) control IR (30 min ischemia and 2 h reperfusion, (3) VNS throughout IR, (4) the arginase inhibitor nor-NOHA+IR, (5) nor-NOHA+VNS+IR, (6) selective α7 nAChR blockade by methyllycaconitine (MLA) followed by VNS throughout IR and (7) MLA+IR.ResultsInfarct size was reduced by VNS compared to control IR (41±3% vs. 67±2% of the myocardium at risk, P
      PubDate: 2017-02-26T20:05:25.318276-05:
      DOI: 10.1111/apha.12861
       
  • Mind the gap: mechanisms regulating the endothelial barrier
    • Authors: Mariya Y. Radeva; Jens Waschke
      Abstract: The endothelial barrier consists of intercellular contacts localized in the cleft between endothelial cells, which is covered by the glycocalyx in a sieve-like manner. Both types of barrier-forming junctions, i.e. the adherens junction (AJ) serving mechanical anchorage and mechanotransduction and the tight junction (TJ) sealing the intercellular space to limit paracelullar permeability, are tethered to the actin cytoskeleton. Under resting conditions, the endothelium thereby builds a selective layer controlling the exchange of fluid and solutes with the surrounding tissue. However, in the situation of an inflammatory response such as in anaphylaxis or sepsis intercellular contacts disintegrate in postcapillary venules leading to intercellular gap formation. The resulting edema can cause shock and multi-organ failure. Therefore, maintenance as well as coordinated opening and closure of interendothelial junctions is tightly regulated. The two principle underlying mechanisms comprise spatiotemporal activity control of the small GTPases Rac1 and RhoA and the balance of the phosphorylation state of AJ proteins. In the resting state, junctional Rac1 and RhoA activity is enhanced by junctional components, actin-binding proteins (ABPs), cAMP signaling and extracellular cues such as sphingosine-1-phosphate (S1P) and angiopoitin-1 (Ang-1). In addition, phosphorylation of AJ components is prevented by junction-associated phosphatases including vascular endothelial protein tyrosine phosphatase (VE-PTP). In contrast, inflammatory mediators inhibiting cAMP/Rac1 signaling cause strong activation of RhoA and induce AJ phosphorylation finally leading to endocytosis and cleavage of VE-cadherin. This results in dissolution of TJs the outcome of which is endothelial barrier breakdown.This article is protected by copyright. All rights reserved.
      PubDate: 2017-02-23T17:35:35.883579-05:
      DOI: 10.1111/apha.12860
       
  • Maternal–fetal cholesterol transport in the second half of mouse
           pregnancy does not involve LDL receptor-related protein 2
    • Authors: M. V. Zwier; M. E. Baardman, T. H. Dijk, A. Jurdzinski, L. J. Wisse, V. W. Bloks, R. M. F. Berger, M. C. DeRuiter, A. K. Groen, T. Plösch
      Abstract: AimLDL receptor-related protein type 2 (LRP2) is highly expressed on both yolk sac and placenta. Mutations in the corresponding gene are associated with severe birth defects in humans, known as Donnai–Barrow syndrome. We here characterized the contribution of LRP2 and maternal plasma cholesterol availability to maternal–fetal cholesterol transport and fetal cholesterol levels in utero in mice.MethodsLrp2+/− mice were mated heterozygously to yield fetuses of all three genotypes. Half of the dams received a 0.5% probucol-enriched diet during gestation to decrease maternal HDL cholesterol. At E13.5, the dams received an injection of D7-labelled cholesterol and were provided with 1-13C acetate-supplemented drinking water. At E16.5, fetal tissues were collected and maternal cholesterol transport and fetal synthesis quantified by isotope enrichments in fetal tissues by GC-MS.ResultsThe Lrp2 genotype did not influence maternal–fetal cholesterol transport and fetal cholesterol. However, lowering of maternal plasma cholesterol levels by probucol significantly reduced maternal–fetal cholesterol transport. In the fetal liver, this was associated with increased cholesterol synthesis rates. No indications were found for an interaction between the Lrp2 genotype and maternal probucol treatment.ConclusionMaternal–fetal cholesterol transport and endogenous fetal cholesterol synthesis depend on maternal cholesterol concentrations but do not involve LRP2 in the second half of murine pregnancy. Our results suggest that the mouse fetus can compensate for decreased maternal cholesterol levels. It remains a relevant question how the delicate system of cholesterol transport and synthesis is regulated in the human fetus and placenta.
      PubDate: 2017-02-22T00:20:31.782042-05:
      DOI: 10.1111/apha.12845
       
  • Repeated maximal-intensity hypoxic exercise superimposed to hypoxic
           residence boosts skeletal muscle transcriptional responses in elite
           team-sport athletes
    • Authors: F. Brocherie; G. P. Millet, G. D'Hulst, R. Van Thienen, L. Deldicque, O. Girard
      Abstract: AimTo determine whether repeated maximal-intensity hypoxic exercise induces larger beneficial adaptations on the hypoxia-inducible factor-1α pathway and its target genes than similar normoxic exercise, when combined with chronic hypoxic exposure.MethodsLowland elite male team-sport athletes underwent 14 days of passive normobaric hypoxic exposure [≥14 h·day−1 at inspired oxygen fraction (FiO2) 14.5–14.2%] with the addition of six maximal-intensity exercise sessions either in normobaric hypoxia (FiO2 ~14.2%; LHTLH; n = 9) or in normoxia (FiO2 20.9%; LHTL; n = 11). A group living in normoxia with no additional maximal-intensity exercise (LLTL; n = 10) served as control. Before (Pre), immediately after (Post-1) and 3 weeks after (Post-2) the intervention, muscle biopsies were obtained from the vastus lateralis.ResultsHypoxia-inducible factor-1α subunit, vascular endothelial growth factor, myoglobin, peroxisome proliferator-activated receptor-gamma coactivator 1-α and mitochondrial transcription factor A mRNA levels increased at Post-1 (all P ≤ 0.05) in LHTLH, but not in LHTL or LLTL, and returned near baseline levels at Post-2. The protein expression of citrate synthase increased in LHTLH (P 
      PubDate: 2017-02-22T00:15:33.898929-05:
      DOI: 10.1111/apha.12851
       
  • The water channel AQP1 is expressed in human atherosclerotic vascular
           lesions and AQP1 deficiency augments angiotensin II-induced
           atherosclerosis in mice
    • Authors: P. Wintmo; S. H. Johansen, P. B. L. Hansen, J. S. Lindholt, S. Urbonavicius, L. M. Rasmussen, P. Bie, B. L. Jensen, J. Stubbe
      Abstract: AimThe water channel aquaporin 1 (AQP1) promotes endothelial cell migration. It was hypothesized that AQP1 promotes neovascularization and growth of atherosclerotic plaques.MethodsAQP1 immunoreactivity and protein abundance was examined in human and murine atherosclerotic lesions and aortic aneurysms. Apolipoprotein E (ApoE) knockout (−/−) and AQP1−/−ApoE−/− mice were developed and fed Western diet (WD) for 8 and 16 weeks to accelerate the atherosclerosis process. In ApoE−/− and AQP1−/−ApoE−/− mice abdominal aortic aneurysms (AAA) were induced by angiotensin II (ANGII) infusion by osmotic minipumps for 4 weeks.ResultsIn human atherosclerotic lesions and AAA, AQP1 immunoreactive protein was associated with intralesional small vessels. In ApoE−/− mouse aorta, APQ1 mRNA levels were increased with time on WD (n = 7–9, P 
      PubDate: 2017-02-22T00:06:00.100597-05:
      DOI: 10.1111/apha.12853
       
  • Hypoxia-stimulated membrane trafficking requires T-Plastin
    • Authors: Marieke Wottawa; Stephanie Naas, Johannes Böttger, Gijsbert J. van Belle, Wiebke Möbius, Natalia H. Revelo, Doris Heidenreich, Melanie von Ahlen, Anke Zieseniss, Katharina Kröhnert, Susanne Lutz, Christof Lenz, Henning Urlaub, Silvio O. Rizzoli, Dörthe M. Katschinski
      Abstract: AimTraffic between the plasma membrane and the endomembrane compartments is an essential feature of eukaryotic cells. The secretory pathway sends cargoes from biosynthetic compartments to the plasma membrane. This is counterbalanced by a retrograde endocytotic route and is essential for cell homeostasis. Cells need to adapt rapidly to environmental challenges like the reduction of pO2 which, however, has not been analyzed in relation to membrane trafficking in detail. Therefore we determined changes in the plasma membrane trafficking in normoxia, hypoxia, and after reoxygenationMethodsMembrane trafficking was analyzed by using the bulk membrane endocytosis marker FM 1-43, the newly developed membrane probe mCLING, wheat germ agglutinin as well as fluorescently labeled choleratoxin subunit B. Additionally, the uptake of specific membrane proteins was determined. In parallel, a non-biased SILAC screen was performed to analyze the abundance of membrane proteins in normoxia and hypoxiaResultsMembrane trafficking was increased in hypoxia and quickly reversed upon reoxygenation. This effect was independent of the hypoxia-inducible factor (HIF) system. Using SILAC technology we identified that the actin bundling protein T-Plastin is recruited to the plasma membrane in hypoxia. By the use of T-Plastin knock down cells we could show that T-Plastin mediates the hypoxia-induced membrane trafficking, which was associated with an increased actin density in the cells as determined by electron microscopyConclusionMembrane trafficking is highly dynamic upon hypoxia. This phenotype is quickly reversible upon re-oxygenation, which suggests that this mechanism participates in the cellular adaptation to hypoxiaThis article is protected by copyright. All rights reserved.
      PubDate: 2017-02-20T16:00:24.23103-05:0
      DOI: 10.1111/apha.12859
       
  • Alpha adrenergic receptor blockade increases capillarisation and
           fractional O2 extraction and lowers blood flow in contracting human
           skeletal muscle
    • Authors: Stefan P. Mortensen; Stuart Egginton, Mads Madsen, Jonas B. Hansen, Gregers D. W. Munch, Ulrik Winning Iepsen, Thorbjörn Åkerström, Bente K. Pedersen, Ylva Hellsten
      Abstract: AimTo investigate the effect of elevated basal shear stress on angiogenesis in humans, and the role of enhanced skeletal muscle capillarisation on blood flow and O2 extraction.MethodsLimb haemodynamics and O2 extraction was measured at rest and during one-leg knee-extensor exercise (12 and 24W) in 10 healthy untrained young men before and after 4 weeks treatment with an α1 receptor-antagonist (Terazosin, 1-2 mg day−1). Corresponding biopsies were taken from the m. vastus lateralis.ResultsResting leg blood flow was increased by 57% 6 hours following Terazosin treatment (P
      PubDate: 2017-02-15T12:50:46.369366-05:
      DOI: 10.1111/apha.12857
       
  • Targeting multiple pathways reduces renal and cardiac fibrosis in rats
           with subtotal nephrectomy followed by coronary ligation
    • Authors: N. R. Oosterhuis; L. G. Bongartz, M. C. Verhaar, C. Cheng, Y. J. Xu, A. Koppen, M. J. Cramer, R. Goldschmeding, C. A. Gaillard, P. A. Doevendans, B. Braam, J. A. Joles
      Abstract: AimMultiple interacting pathways contribute to progression of renal and cardiac damage in chronic kidney disease followed by chronic heart failure (renocardiac syndrome). We hypothesized that simultaneous pharmacological modulation of critical pathways implicated in renocardiac syndrome would effectively reduce fibrosis in and preserve function of heart and kidney.MethodsRats were subjected to subtotal nephrectomy followed 9 weeks later by coronary artery ligation. From week 11 until week 16, rats received vehicle or losartan, or a combination of the NF-kB inhibitor PDTC, the NO donor molsidomine and superoxide dismutase mimetic tempol, or a combination of all four of these plus metoprolol together. At week 16, renal and cardiac structure, function and gene expression were assessed.ResultsIndividual and combined treatments were similarly effective in limiting cardiac fibrosis and further decline in systolic function. Combined treatment with all five drugs reduced renal fibrosis and CTGF gene expression more effectively than other strategies. Combining all five drugs reduced heart rate, inotropy and mean arterial pressure (MAP).ConclusionThus, in our model of chronic renocardiac syndrome, combined treatments similarly decreased cardiac fibrosis and stabilized systolic function as losartan alone, perhaps suggesting a dominant role for a single factor such as angiotensin II type 1 (AT1) receptor activation or inflammation in the network of aberrant systems in the heart. However, tubulointerstitial fibrosis was most effectively reduced by a five-drug regimen, pointing to additive effects of multiple pathophysiological pathways in the kidney.
      PubDate: 2017-02-07T01:40:33.486627-05:
      DOI: 10.1111/apha.12829
       
  • The effect of physical fatigue on oscillatory dynamics of the sensorimotor
           cortex
    • Authors: A. Fry; K. J. Mullinger, G. C. O'Neill, M. J. Brookes, J. P. Folland
      Abstract: AimWhile physical fatigue is known to arise in part from supraspinal mechanisms within the brain, exactly how brain activity is modulated during fatigue is not well understood. Therefore, this study examined how typical neural oscillatory responses to voluntary muscle contractions were affected by fatigue.MethodsEleven healthy adults (age 27 ± 4 years) completed two experimental sessions in a randomized crossover design. Both sessions first assessed baseline maximal voluntary isometric wrist-flexion force (MVFb). Participants then performed an identical series of fourteen test contractions (2 × 100%MVFb, 10 × 40%MVFb, 2 × 100%MVFb) both before and after one of two interventions: forty 12-s contractions at 55%MVFb (fatigue intervention) or 5%MVFb (control intervention). Magnetoencephalography (MEG) was used to characterize both the movement-related mu and beta decrease (MRMD and MRBD) and the post-movement beta rebound (PMBR) within the contralateral sensorimotor cortex during the 40%MVFb test contractions, while the 100%MVFb test contractions were used to monitor physical fatigue.ResultsThe fatigue intervention induced a substantial physical fatigue that endured throughout the post-intervention measurements (28.9–29.5% decrease in MVF, P 
      PubDate: 2017-01-29T02:30:35.859182-05:
      DOI: 10.1111/apha.12843
       
  • Enhanced contractility of intraparenchymal arterioles after global
           cerebral ischaemia in rat – new insights into the development of delayed
           cerebral hypoperfusion
    • Authors: S. Spray; S. E. Johansson, A. Radziwon-Balicka, K. A. Haanes, K. Warfvinge, G. K. Povlsen, P. A. T. Kelly, L. Edvinsson
      Abstract: AimDelayed cerebral hypoperfusion is a secondary complication found in the days after transient global cerebral ischaemia that worsens the ischaemic damage inflicted by the initial transient episode of global cerebral ischaemia. A recent study demonstrated increased cerebral vasoconstriction in the large arteries on the brain surface (pial arteries) after global cerebral ischaemia. However, smaller arterioles inside the brain (parenchymal arterioles) are equally important in the regulation of cerebral blood flow and yet their pathophysiology after global cerebral ischaemia is largely unknown. Therefore, we investigated whether increased contractility occurs in the intraparenchymal arterioles.MethodsGlobal cerebral ischaemia was induced in male Wistar rats by bilateral common carotid occlusion for 15 min combined with hypovolaemia. Regional cerebral blood flow was determined by quantitative autoradiography. Intraparenchymal arterioles were isolated and pressurized, and concentration–response curves to endothelin-1 with and without the endothelin B receptor-selective antagonist BQ788 was generated. Endothelin B receptor expression was investigated by quantitative flow cytometry and immunohistochemistry.ResultsWe observed increased endothelin-1-mediated contractility of parenchymal arterioles correlating with reduced cerebral blood flow of the cortex, hippocampus and caudate nucleus 48 h after global cerebral ischaemia. The increased endothelin-1-mediated contractility was abolished by BQ788, and the vascular smooth muscle cell-specific expression of endothelin B receptors was significantly increased after global cerebral ischaemia.ConclusionIncreased endothelin-1-mediated contractility and expression of endothelin B receptors in the intraparenchymal vasculature contributes to the development of delayed cerebral hypoperfusion after global cerebral ischaemia in combination with vascular changes of the pial vasculature.
      PubDate: 2017-01-29T02:15:39.666564-05:
      DOI: 10.1111/apha.12834
       
  • A comparison of left and right atrial fibroblasts reveals different
           collagen production activity and stress-induced mitogen-activated protein
           kinase signalling in rats
    • Authors: C.-C. Chung; Y.-H. Kao, C.-J. Yao, Y.-K. Lin, Y.-J. Chen
      Abstract: AimAtrial fibrosis plays a pivotal role in the pathophysiology of heart failure (HF). The left atrium (LA) experiences greater fibrosis than the right atrium (RA) during HF. It is not clear whether LA cardiac fibroblasts contain distinctive activities that predispose LA to fibrosis.MethodsLA and RA fibrosis were evaluated in healthy and isoproterenol-induced HF Sprague Dawley rats. Rat LA and RA primary isolated fibroblasts were subjected to proliferation assay, oxidative stress assay, cell migration analysis, collagen measurement, cytokine array and Western blot.ResultsHealthy rat LA and RA had a similar extent of collagen deposition. HF significantly increased fibrosis to a greater severity in LA than in RA. Compared to isolated RA fibroblasts, the in vitro experiments showed that isolated LA fibroblasts had higher oxidative stress and exhibited higher collagen, transforming growth factor-β1, connective tissue growth factor production and less vascular endothelial growth factor (VEGF) production, but had similar migration, myofibroblast differentiation and proliferation activities. VEGF significantly increased the collagen production ability of LA fibroblasts, but not RA fibroblasts. LA fibroblasts had more phosphorylated ERK1/2 and P38 expression. ERK inhibitor (PD98059, 50 μmol L−1) significantly attenuated collagen production and increased VEGF production in RA fibroblasts but not in LA fibroblasts. P38 inhibitor (SB203580, 30 μmol L−1) significantly attenuated collagen production in LA fibroblasts but not in RA fibroblasts. P38 inhibitor also significantly increased VEGF production in RA and LA fibroblasts.ConclusionsDifferences in profibrotic activity between LA and RA fibroblasts may be caused by different responses to mitogen-activated protein kinase signalling.
      PubDate: 2017-01-16T04:06:13.298552-05:
      DOI: 10.1111/apha.12835
       
  • Neuromuscular changes and the rapid adaptation following a bout of
           damaging eccentric exercise
    • Authors: S. Goodall; K. Thomas, M. Barwood, K. Keane, J. T. Gonzalez, A. St Clair Gibson, G. Howatson
      Abstract: IntroductionAn initial bout of eccentric exercise is known to protect against muscle damage following a repeated bout of the same exercise; however, the neuromuscular adaptations owing to this phenomenon are unknown.AimTo determine whether neuromuscular disturbances are modulated following a repeated bout of eccentric exercise.MethodsFollowing eccentric exercise performed with the elbow flexors, we measured maximal voluntary force, resting twitch force, muscle soreness, creatine kinase (CK) and voluntary activation (VA) using motor point and motor cortex stimulation at baseline, immediately post-exercise and at 1, 2, 3, 4 and 7 days post-exercise on two occasions, separated by 3 weeks.ResultsSignificant muscle damage and fatigue were evident following the first exercise bout; maximal voluntary contraction (MVC) was reduced immediately by 35% and remained depressed at 7 days post-exercise. Soreness and CK release peaked at 3 and 4 days post-exercise respectively. Resting twitch force remained significantly reduced at 7 days (−48%), whilst VA measured with motor point and motor cortex stimulation was reduced until 2 and 3 days respectively. A repeated bout effect (RBE) was observed with attenuated soreness and CK release and a quicker recovery of MVC and resting twitch force. A similar decrement in VA was observed following both bouts; however, following the repeated bout there was a significantly smaller reduction in, and a faster recovery of, VA measured using motor cortical stimulation.ConclusionOur data suggest that the RBE may be explained, partly, by a modification in motor corticospinal drive.
      PubDate: 2017-01-05T01:11:10.222564-05:
      DOI: 10.1111/apha.12844
       
  • Issue Information
    • Pages: 301 - 302
      PubDate: 2017-06-13T05:25:48.517531-05:
      DOI: 10.1111/apha.12786
       
 
 
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