Issue Archive

MECHANISM OF INTRACELLULAR CALCIUM HOMEOSTASIS IN HEAT-EXPOSED CARDIOMYOCYTES OF RATS

YANG XIAO-HAO, LI WEN-XUAN, CHENG SU-QI, CHEN XI-JING

(Institute of Health and Environmental Medicine, Tianjin 300050)

Abstract

The activity of Cat+-ATPase and calcium content were measured in sarcoplasmic reticulum (SR) and mitochrondria of myocardium from 40 adult female Wistar rats after exposure to 3 7℃，39℃，41'C and 4 3℃for 40 min respectively in vitro. The 45Ca uptake，intracellular free CaZ+ concentration(ECaZ+]，)and the relatively active calmodulin content were also observed in cultured cardiomyocytes from 120 neonatal Wistar rats under the same condition of heat exposure. The results showed that(1)the activity of Caz+-ATPase of SR and mitochrondria of myocardium decreased after heat exposure，(2) the calcium content of SR and mitochrondria also showed a tendency of decrease with increase of exposure temperature，(3) the "Ca uptake and mean[CaZ+];
increased，whereas the calmodulin content decreased. It is suggested that disturbances of intracellular calcium homeostasis may be responsible for cardiac functional disorder after heat exposure.

Key words: :heat exposure;Cardiomyocyte;intracellular calcium

Received: 　　Accepted:

Corresponding author: 　　E-mail:

Citing This Article：

YANG XIAO-HAO, LI WEN-XUAN, CHENG SU-QI, CHEN XI-JING. MECHANISM OF INTRACELLULAR CALCIUM HOMEOSTASIS IN HEAT-EXPOSED CARDIOMYOCYTES OF RATS. Acta Physiol Sin 1996; 48 (5): (in Chinese with English abstract).