PMID: 10549Oct 15, 1976

Influence of low extracellular pH upon the Ca inward current and isometric contractile force in mammalian ventricular myocardium

Pflügers Archiv : European journal of physiology
M KohlhardtH R Figulla


In isolated papillary muscles of cats the changes in Ca inward current and isometric contractile force following a decrease of extracellular pH from 7.4 to 5.5 were studied. The Ca current was analyzed (a) by measuring the upstroke velocity of Ca-mediated action potentials and (b) in voltage clamp experiments using the double sucrose gap technique. 1. At a pH of 5.5 the upstroke velocity of the Ca-mediated action potential decreased to 65% of the control, while overshoot and action potential duration remained almost unchanged. Furthermore, the relative refractory period was prolonged and in some cases, a "Wenckebach-like" phenomenon occurred. In voltage clamp experiments, the slow inward current was found to be diminished to 50-60% of the initial control value and over a broad voltage range the current voltage relationship curve was shifted to weaker currents. Acidosis did not influence the steady state inactivation but altered the kinetics of inactivation of the slow inward current and induced an increase of tauinactivation and taurecovery. This indicates that acidosis exerts a complex effect on the slow membrane channel. 2. The normal response of the Ca current towards variations of the extracellular Ca concentration (0.5-4 m...Continue Reading


Sep 1, 1975·The American Journal of Physiology·P A Poole-Wilson, G A Langer
Jun 10, 1975·Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences·B HilleB I Shapiro
Sep 1, 1975·Journal of Molecular and Cellular Cardiology·J M ChesnaisJ M Vassas
Mar 22, 1975·Pflügers Archiv : European journal of physiology·M KohlhardtA Herdey
Jun 1, 1973·The Journal of General Physiology·A M Woodhull
Jan 1, 1974·Pflügers Archiv : European journal of physiology·H Drouin, B Neumcke
Jan 1, 1973·Progress in Biophysics and Molecular Biology·H Reuter
Jan 1, 1972·Pflügers Archiv : European journal of physiology·S Bosteels, E Carmeliet
Jan 1, 1972·Pflügers Archiv : European journal of physiology·W New, W Trautwein
Nov 25, 1970·Biochemical and Biophysical Research Communications·Y Nakamaru, A Schwartz
Nov 1, 1965·The American Journal of Physiology·E S BensonR Vijums
Sep 1, 1952·The American Journal of Physiology·E B BROWN, F MILLER
Aug 16, 1955·Proceedings of the Royal Society of London. Series B, Containing Papers of a Biological Character·A V HILL
Sep 1, 1957·Circulation Research·G G NAHAS
Nov 1, 1958·The American Journal of Physiology·W T McELROYE B BROWN
May 1, 1963·The American Journal of Physiology·E B BROWN, B GOOTT
Jul 1, 1963·Circulation Research·H H BENDIXENW E FLACKE
Dec 1, 1970·The Journal of Membrane Biology·H G HaasH M Einwächter


Oct 1, 1982·Pflügers Archiv : European journal of physiology·G Isenberg, U Klöckner
Sep 1, 1982·Pflügers Archiv : European journal of physiology·Y Kurachi
Jan 1, 1988·Cardiovascular Drugs and Therapy·W A Coetzee
Jan 1, 1988·Cardiovascular Drugs and Therapy·W MarkiewiczJ Wikman-Coffelt
Feb 1, 1981·Journal of Molecular and Cellular Cardiology·A YataniM Goto
Sep 1, 1995·Journal of Molecular and Cellular Cardiology·G J Rozanski, R C Witt
Jul 20, 2002·Life Sciences·Kaoru HattoriI Muramatsu
Jan 1, 1983·Progress in Cardiovascular Diseases·E C Keung, R S Aronson
Jan 1, 1985·Journal of Molecular and Cellular Cardiology·B VanheelI Leusen
Jul 2, 2008·Brazilian Journal of Medical and Biological Research = Revista Brasileira De Pesquisas Médicas E Biológicas·A C CelottoP R B Evora
Feb 1, 1987·Circulation Research·D G Allen, C H Orchard
Oct 1, 1988·Circulation Research·R J SolaroD G Allen
May 1, 1978·Circulation Research·E Carmeliet
Mar 20, 1998·Circulation Research·M C Camilión de HurtadoH E Cingolani
Aug 1, 1981·Circulation Research·R A AltschuldG P Brierley
Dec 1, 1978·Circulation Research·A W Wiegner, S H Bing
Jul 1, 1987·The American Journal of Physiology·D Kim, T W Smith
Sep 1, 1989·The Journal of Pharmacy and Pharmacology·M Shahid, I W Rodger

Related Concepts

Nerve Impulses
Felis catus
Hydrogen-Ion Concentration
Resting Potentials
Myocardial Contraction

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Neural Activity: Imaging

Imaging of neural activity in vivo has developed rapidly recently with the advancement of fluorescence microscopy, including new applications using miniaturized microscopes (miniscopes). This feed follows the progress in this growing field.

The Tendon Seed Network

Tendons are rich in the extracellular matrix and are abundant throughout the body providing essential roles including structure and mobility. The transcriptome of tendons is being compiled to understand the micro-anatomical functioning of tendons. Discover the latest research pertaining to the Tendon Seed Network here.

Myocardial Stunning

Myocardial stunning is a mechanical dysfunction that persists after reperfusion of previously ischemic tissue in the absence of irreversible damage including myocardial necrosis. Here is the latest research.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.


Incretins are metabolic hormones that stimulate a decrease in glucose levels in the blood and they have been implicated in glycemic regulation in the remission phase of type 1 diabetes. Here is the latest research.

Chromatin Regulation and Circadian Clocks

The circadian clock plays an important role in regulating transcriptional dynamics through changes in chromatin folding and remodelling. Discover the latest research on Chromatin Regulation and Circadian Clocks here.

Long COVID-19

“Long Covid-19” describes illness in patients who are reporting long-lasting effects of the SARS-CoV-19 infection, often long after they have recovered from acute Covid-19. Ongoing health issues often reported include low exercise tolerance and breathing difficulties, chronic tiredness, and mental health problems such as post-traumatic stress disorder and depression. This feed follows the latest research into Long Covid.

Spatio-Temporal Regulation of DNA Repair

DNA repair is a complex process regulated by several different classes of enzymes, including ligases, endonucleases, and polymerases. This feed focuses on the spatial and temporal regulation that accompanies DNA damage signaling and repair enzymes and processes.