Na/Ca exchange plays a role in calcium homeostasis and calcium-induced calcium release of cardiac myocytes
- VernacularTitle:Na/Ca交换在心肌细胞Ca~(2+)平衡和CICR过程中的作用
- Author:
Lihua LI
;
Leiming REN
- Publication Type:Journal Article
- Keywords:
Ca2+;
Na/Ca exchange;
calcium induced calcium release;
cardiomyocyte
- From:
Chinese Pharmacological Bulletin
1998;0(S1):-
- CountryChina
- Language:Chinese
-
Abstract:
ABSTRACT Calcium homeostasis is of crucial importance for the function of cardial myocytes in normal electrical and mechanical processes. The sarcoplasmic reticular Ca-ATPase and the sar-colemmic Na/Ca exchanger contribute mainly to the steady state of calcium in the myoplasm. The Na/Ca exchanger serves as the principal calcium extrusion mechanism and regulates calcium content of the sarcoplasmic reticulum by regulating the resting [Ca2+]i level, through which the Na/Ca exchanger regulates the force of contraction sequentially. Very small calcium entry can trigger significant sarcoplasmic reticular calcium release (CICR). During the upstroke and plateau phasesof the action potential, There is evidence that indicates Ca2+ influx via the Na/Ca exchanger, and the depolarisation-induced calcium entry on Na/Ca exchange may contribute mainly to triggering intra-cellular calcium release. Na/Ca exchange should be reevaluated as a route through which Ca2+, as a triggering signal, enters cardiac myocyte during excitation-contraction coupling.
