摘要
心肌细胞内钙离子对心功能的调节有着极其重要的作用。本研究观察了不同热应激强度下大鼠心肌细胞内质网、线粒体中钙含量，Ｃａ２＋－ＡＴＰ酶活力，内质网Ｃａ２＋主动转运速率及心肌ＡＴＰ含量的变化。研究结果表明，热应激大鼠心肌细胞内质网、线粒体钙含量随肛温升高显著下降；大鼠肛温达４２℃时，其钙含量分别较对照下降３２．２％和４６．５％；心肌细胞内质网和线粒体Ｃａ２＋－ＡＴＰ酶活力亦明显降低，线粒体Ｃａ２＋－ＡＴＰ酶活力下降幅度更为激烈。热应激大鼠心肌内质网Ｃａ２＋主动转运速率和Ｃａ２＋－ＡＴＰ酶活力变化趋势相同，且两者呈密切相关关系。热应激大鼠心肌ＡＴＰ含量亦随肛温升高大幅度降低，当动物肛温超过４２℃时，其可降至对照动物的３７．５％；热应激大鼠心肌ＡＴＰ含量的变化与内质网Ｃａ２＋－ＡＴＰ酶活力关系密切。实验结果提示：热应激心肌细胞质膜受损所致细胞Ｃａ２＋主动转运功能紊乱及心肌能量代谢障碍是心肌钙稳态失调的主要原因；心肌细胞钙代谢紊乱是诱导心肌细胞严重受损，导致热应激机体心血管功能失调。
Calcium contents of sarcoplasmic reticulum (SR) and mitochondria (Mit) of myocardium in rats exposed to different heat environment were measured. The rate of Ca 2+ active transportation in SR and ATP content in myocardium were also observed. The results showed that the calcium content in SR and Mit decreased gradually as rectal temperature increased. When Tr rose above42℃, calcium content in SR and Mit decreased respectively by 32.2% and 46.5% as compared with the control. There were similar decline tendency of the activity of Ca 2+ ATPase in SR and Mit. When Tr increased, the rate of Ca 2+ active transportation in SR also decreased, which was closely correlated to the activity of Ca 2+ ATPase. The results suggested that the disorder of Ca 2+ active transportation and energy metabolism, which resulted from heat injury of cellular membrane, is the main cause of Ca 2+ stability disorder in myocardiocyte, the disorder of Ca 2+ metabolism may result in several injury of myocardiocyte and cardiac function disorder, even heart failure in heat stress.
出处
《中国应用生理学杂志》
CAS
CSCD
1998年第2期161-165,共5页
Chinese Journal of Applied Physiology
关键词
热应激
心肌
钙代谢
heat stress
myocardium
calcium metabolism
