短暂缺氧对心肌细胞K_(ATP)通道的影响

The Effect on Cardiac Plasma Membrane K_(ATP) Channel by Brief Hypoxia

:【目的】探讨KATP通道在心肌缺血预适应 (IP)中的作用。【方法】用膜片钳单通道记录技术的细胞贴附式研究急性短暂缺氧复氧对新鲜分离的豚鼠心肌细胞细胞膜KATP通道影响。【结果】短暂缺氧 10min可明显引起细胞膜KATP通道的开放 ,缺氧诱导的KATP通道的开放以簇状开放为主。复氧 2min及用 2mmol/LATP可抑制通道开放 ,其电导值为 89 7pS。缺氧使通道开放概率 (Po)明显增加 ,并可诱发通道出现二级开放。【结论】短暂缺氧可以激活心肌细胞膜KATP通道的开放 ,说明心肌细胞膜KATP通道参与了IP的保护作用。

Objective In order to study the role of the cardiac myocyte membrane K ATP channel in ischemic preconditioning(IP) in vitro. Method The effect of 10 min hypoxia on K ATP channel of isolated ventricular myocyte was observed, by using patch clamp technique (cell-attached configuration). Result The result show that K ATP channel can be easily opened by 10 min brief hypoxia, and inhibited by reoxygenation within 2 min or by 2 mmol/L ATP. The opening of K ATP channel was in burst. The single-channel conductance activated by hypoxia was 89 7 pS, the P o (open state probability) was increased by hypoxia, and the secondary opening of K ATP channel was also induced. Conclusion Brief hypoxia could activated cardic plasma membrane K ATP channel and the results proved that K ATP channel should take part in the IP.