缺氧预处理对人心肌细胞缺氧复氧损伤的影响及其机制

EFFECTS OF HYPOXIC PRECONDITIONING ON HYPOXIA/REOXYGENATION OF HUMAN CARDIOMYOCYTES AND ITS MECHANISM

探讨缺氧预处理（PC）对于人类心肌细胞缺氧复氧（H／R）损伤的影响及其机制。方法：在体外分离的人心房和心室肌细胞的H／R模型上观察缺氧PC的作用，及蛋白激酶C（PKC）抑制剂与蛋白磷酸酶激动剂和抑制剂对PC现象的影响。结果：缺氧PC明显减轻H／R造成的心肌细胞损伤，PKC抑制剂H_7和蛋白磷酸酶激动剂BDM分别完全消除PC的细胞保护，而蛋白磷酸酶抑制剂OA则能模拟PC的上述保护效应。结论：人类心肌细胞存在缺氧PC现象，其保护机制可能涉及PKC激活和蛋白磷酸化过程。

Objective: To investigate the effects of hypoxic preconditioning (PC) on hypoxia/reoxygenation (H/R) injury of isolated human cardiomyocytes and its mechanisms. Methods: In a hypoxia/reoxygenayion (H/R) model of isolated human artrial and ventricular muscle cells, the present study observes the effects of PC on H/R injury, and studies the role of protein kinase C (PKC) inhibitor, activator and inhibitor of protein phosphatase on PC. Results: Hypoxic PC attenuated the H/R injury on cardiomyocytes. Preincubated the cardiomyocytes with protein kinase C (PKC) inhibitor H7 or protein phosphatase activator BDM abolished respectively, while protein phosphatase inhibitor OA mimicked PC's protective effect. Conclusion: Human cardiomyocytes have PC phenomenon, and the protective mechanism might involve the activation of PKC and protein phosphorylation reaction.