目的　探讨吡那地尔 (Pinacidil)预处理 (preconditioning ,PC)对失血性休克大鼠保护作用的机制。　方法　 (1)大鼠 90只 ,随机分为正常组 (N组 ,10只 )、对照组 (C组 ,40只 )和预处理组(PC组 ,40只 ) ,PC组大鼠用Pinacidil进行预处理 ,2 4h后将对照组和预处理组大鼠复制成失血性休克模型 ,用Westernblot方法观察不同时相点大鼠心肌组织细胞型磷脂酶A2 (cPLA2 )的表达变化 ;(2 )大鼠 6 0只 ,随机分为对照组 (C组 ,30只 )和预处理组 (PC组 ,30只 ) ,PC组大鼠用Pinacidil进行预处理 ,然后分别在 2 4,48,72h 3个不同时间点将两组大鼠复制成失血性休克模型 ,用Westernblot方法观察PC对大鼠心肌和肝脏组织热休克蛋白 70 (hsp70 )表达的影响。　结果　 (1)PC组心肌组织cPLA2 的表达较弱 ,而C组表达很强 ;(2 )C组hsp70表达很弱或检测不到 ,PC组心肌和肝脏hsp70表达很强 ,2 4h达到高峰 ,48h和 72h逐渐减弱。　结论　Pinacidil预处理可能是通过诱导hsp70过度表达和抑制PLA2 的表达保护“休克细胞” ,从而保护失血性休克大鼠的心肌和肝脏组织 Objective To investigate the protective effect of Pinacidil preconditioning (PC) on hemorrhagic shock in rats. Methods Ninety rats were randomly divided into normal group (N group, 10 rats), control group (C group, 40 rats) and pretreatment group (PC group, 40 rats). Rats in PC group were treated with Pinacidil The rats in control group and preconditioning group were duplicated into hemorrhagic shock model after 24 hours. Western blotting was used to observe the change of cPLA2 expression in rat myocardium at different time points. (2) The rats were randomly divided into control group (30 rats in group C) and 30 rats in pretreatment group (PC group, 30 rats). Rats in PC group were pretreated with Pinacidil and then treated with 3, 4, Two groups of rats were duplicated into hemorrhagic shock model at different time points, and the effect of PC on the expression of heat shock protein 70 (hsp70) in myocardium and liver tissue was observed by Western blot. Results (1) The expression of cPLA2 in PC group was weak and the expression in group C was strong. (2) The expression of hsp70 in group C was weak or undetectable. The expression of hsp70 in myocardium and liver of PC group was very strong and peaked at 24 hours. 48h and 72h gradually weakened. Conclusion Pinacidil preconditioning may protect the “shock cells” by inducing the overexpression of hsp70 and inhibiting the expression of PLA2, so as to protect the myocardium and liver tissue of hemorrhagic shock rats