Ca2+ cycling in heart cells from ground squirrels: adaptive strategies for intracellular Ca2+ homeostasis.

ABSTRACT: Heart tissues from hibernating mammals, such as ground squirrels, are able to endure hypothermia, hypoxia and other extreme insulting factors that are fatal for human and nonhibernating mammals. This study was designed to understand adaptive mechanisms involved in intracellular Ca(2+) homeostasis in cardiomyocytes from the mammalian hibernator, ground squirrel, compared to rat. Electrophysiological and confocal imaging experiments showed that the voltage-dependence of L-type Ca(2+) current (I(Ca)) was shifted to higher potentials in ventricular myocytes from ground squirrels vs. rats. The elevated threshold of I(Ca) did not compromise the Ca(2+)-induced Ca(2+) release, because a higher depolarization rate and a longer duration of action potential compensated the voltage shift of I(Ca). Bot

SUBMITTER: Li XC 

PROVIDER: S-EPMC3173481 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature