Intracellular calcium homeostasis in cardiac myocytes.

Calcium homeostasis in cardiac myocytes results from the integrated function of transsarcolemmal Ca2+ influx and efflux pathways modulated by membrane potential and from intracellular Ca2+ uptake and release caused predominantly by SR function. These processes can be importantly altered in different disease states as well as by pharmacological agents, and the resulting changes in systolic and diastolic [Ca2+]i can cause clinically significant alterations in contraction and relaxation of the heart. It may be anticipated that a rapid increase in our understanding of the pathophysiology of Ca2+ homeostasis in cardiac myocytes will be forthcoming as the powerful new tools of molecular and structural biology are used to investigate the regulation of Ca2+ transport systems.