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缺氧预处理对乳鼠心肌细胞蛋白激酶C活性的影响

刘秀华, 庞永政, 唐朝枢, 苏静怡

(北京医科大学心血管基础研究所，北京100083)

摘要

在培养的乳鼠心肌细胞缺氧/复氧(A/R)模型上，观察缺氧预处理(APC)的细胞保护作用及其对细胞蛋白激酶C(PKC)活性和蛋白磷酸化的影响。结果表明，APC可减轻心肌细胞的H/R振伤:提高细胞存活率((P< 0. 01)，减少细胞脂质过氧化产物(MDA)生成((P<0. 01)及细胞内乳酥脱氢酶((LDH)和蛋白质的漏出((P<0. 01)。模拟APC的短暂缺氧(TA)显著激活PKC (125. 0土11. 2 vs对照组52.1士 8.9 pmol Pi /106ce11s,P<0. O1)，使心肌细胞内分子量为66 kD和31 kD配蛋白条带32p掺入增加;PKC抑制剂H,完全消除APC对心肌细胞的保护作用，并抑制了短暂缺氧引起的PKC激活及蛋白磷酸化反应。磷酸酶抑制剂OA模拟，而激动剂BDM完全消除APC的保护作用;提示PKC介导了APC对心肌细胞的保护，其机理涉及PKC对其底物蛋白的磷酸化。

关键词： 缺氧预处理; 心肌细胞; 蛋白激酶C; 蛋白磷酸化

EFFECT OF ANOXIC PRECONDITIONING ON PROTEIN KINASEC ACTIVITY IN NEONATAL RAT CARDIOMYOCYTES

LIU XIU HUA, PANG YONG ZHENG, TANG CHAO-SHU, SU JING-YI

(Beijing Institute of Cardiovascular Research, Beijing Medical University,1000083)

Abstract

In a model of anoxia /reoxygenation (A/R) of cultured rat cardiomyocytes，protection of cellular damage，activation of protein kinase C (PKC) and PKC-mediated protein phosphorylation by anoxic preconditioning (APC) can be demonstrated as shown by the increase of cell viability，attenuation of formation of lipid peroxides (MDA)and lowering of the leakage of lactate dehydrogenase (LDH) and protein from cells. The results also show that transient anoxia mimicked the outcomes of activation of PKC as
shown by increased incorporation of 31p，especially in the 66 kD and 31 kD protein fractions. Preincubation of cardiomyocytes with H, (an inhibitor of PKC)completely abolished these protective effects of transient anoxia. Protein phosphatase inhibitor OA mimicked the protective effects of A/R，while protein phosphatase activator BDM in duced a complete abolishment. In short，we conclude that the protective effect of APC
is medicated by activation of PKC.

Key words: hypoxic preconditioning;Cardiomyocyte;Protein kinase C;protein phosphorylation

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引用本文：

刘秀华, 庞永政, 唐朝枢, 苏静怡. 缺氧预处理对乳鼠心肌细胞蛋白激酶C活性的影响[J]. 生理学报 1997; 49 (4): .

LIU XIU HUA, PANG YONG ZHENG, TANG CHAO-SHU, SU JING-YI. EFFECT OF ANOXIC PRECONDITIONING ON PROTEIN KINASEC ACTIVITY IN NEONATAL RAT CARDIOMYOCYTES . Acta Physiol Sin 1997; 49 (4): (in Chinese with English abstract).