大鼠心肌组织中热休克蛋白70水平与NO、NO合酶表达以及心肌细胞凋亡的关系

目的 探讨离体大鼠心肌组织中热休克蛋白70(HSP70)水平与NO、NO合酶(NOS)表达以及心肌细胞凋亡的关系.方法 将Wistar大鼠分为2组,实验组腹腔注射重酒石酸去甲肾上腺素,24 h后取离体心脏,灌注Histidine-trytophan-ketoglurate(HTK)液,置于4℃HTK液中保存3 h,然后以Krebs-Henseleit(K-H)液行Langendorff灌流2 h;对照组腹腔注射蒸馏水0.5 ml,24 h后取离体心脏,冷保存和Langendorff灌流同实验组.灌流结束后,取心肌组织,测定其HSP70、NO和NOS的含量以及心肌细胞凋亡指数.结果 实验组心肌组织中HSP70、NO和NOS的含量分别为(17.8±1.8)%、(8.7±1.7)μmol/g组织和(0.91±0.18)IU/mg组织,均明显高于对照组(P<0.01),而心肌细胞凋亡指数为(5.6±1.0)%,明显低于对照组(P<0.01).HSP70含量与细胞凋亡指数呈负相关(r=-0.946,P<0.01),与NO含量(r=0.087,P<0.01)和NOS含量(r=0.953,P<0.01)呈正相关.结论 心肌组织中HSP70与NO和NOS的表达呈正相关,而与心肌细胞的凋亡呈负相关,促进HSP70的表达可能有利于抑制心肌细胞凋亡.

Effects of heat shock protein 70 on myocardial cell apoptosis and expression of nitric oxide and nitric oxide synthnase in isolated rat heart

Objective To investigate the effects of heat shock protein 70 (HSP70) on myocardial cell apoptosis,expression of nitric oxide(NO)and nitric oxide synthnase(NOS).Methods Eighteen Wistar rats were randomly divided into two groups.In experiment group (E),norepinephrine was injected intraperitioneally,and 24 h later isolated hearts were stored in 4℃ for 3 h with Histidine-trytophan-ketoglurate(HTK),and then perfused with Krebs-Henseleit solution for 2 h by Langendorff model. In control group(C),normal saline(0.5 ml)was injected intraperitioneally,and 24 h later isolated hearts were stored in 4℃ for 3 h with HTK solutions.and then perfused with Krebs-Henseleit solution for 2 h by Langendorff model .The myocardial HSP70 content,myocardial apoptosis index and the expression of NO and NOS were detected.Results HSP70,NO and NOS contents in E group were higher than in C group.The myocardial apoptosis index in E group was lower than in C group.The HSP70 content had a positive correlation with NO (r=0.887,P<0.01) and NOS(r=0.953,P<0.01)contents,and a negative correlation with myocardial apoptosis index (r=-0.946,P<0.01).Conclusion HSP70 can obviously decrease myocardial cell apoptosis and increase the expression of NO,and NOS in isolated rat hearts.