心肌缺氧对大鼠心肌细胞内游离钙浓度的作用  

THE EFFECTS OF MYOCARDIAL HYPOXIA ON CARDIAC CYTOSOLIC FREE CALCIUM CONCENTRATION IN RATS

作　　者：陈英茂[1] 詹澄扬[1] 潘敬运[1] 

机构地区：[1]广州中山医科大学生理学教研室,承德医学院低温生理研究室

出　　处：《中国应用生理学杂志》1995年第2期102-105,共4页Chinese Journal of Applied Physiology

摘　　要：本实验用ｆｕｒａ－２荧光技术研究离体鼠心缺氧期间心肌细胞内游离钙浓度（［Ｃａ￣（２＋）］＿ｉ）增加的机制。实验结果为：（１）Ｋｒｅｂｓ－Ｈｅｎｓｅｌｅｉｔ（Ｋ－Ｈ）液缺氧灌流离体鼠心脏引起［Ｃａ￣（２＋）］＿ｉ先慢后快地增加。（２）无钙液缺氧灌流，仍能引起［Ｃａ￣（２＋）］＿ｉ增加。（３）含异搏定（１．１×１０￣（－５）ｍｏｌ／Ｌ）的Ｋ－Ｈ液缺氧灌流［Ｃａ￣（２＋）］＿ｉ的变化类似无钙液缺氧灌流，而且两者引起的［Ｃａ￣（２＋）］＿ｉ增加，明显低于Ｋ－Ｈ液缺氧灌流。（４）Ｌｉｃｌ取代Ｋ－Ｈ液中ＮａＣｌ缺氧灌流时引起［Ｃａ￣（２＋）］＿ｉ增加速率显著快于Ｋ－Ｈ液缺氧灌流。上述结果表明：心肌缺氧时［Ｃａ￣（２＋）］＿ｉ增加与胞内钙释放、胞外钙通过钙通道内流及Ｎａ￣＋－Ｃａ￣（２＋）交换有关。The mechanism of increase in rat cardiac cytosolic free calcium concentration([ Ca￣(2+))_i)during hypoxia was investigated using fura-2 fluorescence technique. The main results were asfollows:(1)Perfusion of isolated rat hearts with hypoxic and substrate-free K-H solutioncaused an increase in(Ca￣ (2+))_i at increasing speed.(2) Perfusion with the calcium-free hypoxicand substrate-free K-H solution still led to an increase in(Ca ￣(2+))_i.(3)The increase in[Ca￣(2+))_ i induced by perfusion with the K-H solution containing verapamil (1.1 × 10(-5)mol / 1)was similar to that with the calcium-free K-H solution, and the increase in (Ca￣(2+))_ i in bothcases was significantly less than that during hypoxic K-H solution perfusion. (4)The rate of in-crease in ( Ca￣ (2+))_ i during hypoxic perfusion with low-sodium K-H solution was significantlyhigher than that with k-H solution. These results suggest that the increase in(Ca￣(2+))_i is relat-ed to the release of Ca￣(2+) from intracellular pool, Ca￣(2+) influx via calcium channel andNa￣+-Ca￣(2+) exchange during myocardial hypoxia.

关 键 词：心肌 缺氧 胞浆游离钙 

分 类 号：R331.31[医药卫生—人体生理学]