Intracellular pH regulation in heart.
Intracellular pH (pHi) is an important modulator of cardiac excitation and contraction, and a potent trigger of electrical arrhythmia. This review outlines the intracellular and membrane mechanisms that control pHi in the cardiac myocyte. We consider the kinetic regulation of sarcolemmal H+, OH- and HCO3- transporters by pH, and by receptor-coupled intracellular signalling systems. We also consider how activity of these pHi effector proteins is coordinated spatially in the myocardium by intracellular mobile buffer shuttles, gap junctional channels and carbonic anhydrase enzymes. Finally, we review the impact of pHi regulatory proteins on intracellular Ca2+ signalling, and their participation in clinical disorders such as myocardial ischaemia, maladaptive hypertrophy and heart failure. Such multiple effects emphasise the fundamental role that pHi regulation plays in the heart.
Vaughan-Jones
Richard D
RD
Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Oxford, Parks Road, OX1 3PT, UK. richard.vaughan-jones@physiol.ox.ac.uk
Spitzer
Kenneth W
KW
Swietach
Pawel
P
D000818:Animals; D020013:Calcium Signaling; D017629:Gap Junctions / Q000378:metabolism; D006331:Heart Diseases / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D017136:Ion Transport; D007700:Kinetics; D009124:Muscle Proteins / Q000096:biosynthesis; D009200:Myocardial Contraction; D009206:Myocardium / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000378:metabolism*
D009124:Muscle Proteins