细胞凋亡抑制参与联合应用吗啡和肢体远隔缺血后处理的心肌保护作用

Apoptotic inhibition is involved in protection of combining morphine and limb remote ischemic postconditioning against myocardial ischemia/reperfusion injury

探讨抗细胞凋亡在联合应用吗啡和肢体远隔缺血后处理（remote ischemic postconditioning, RIP）心肌保护中的作用。 方法 采用大鼠在体心肌缺血/再灌注损伤（ischemia/reperfusion injury, I/RI）模型，根据随机数字表法将60只SD大鼠分为4组（每组15只）：缺血/再灌注（ischemia/reperfusion, I/R）组（I/R组）、肢体RIP组（RIP组）、吗啡后处理组（M组）以及联合应用吗啡和肢体RIP组（M＋RIP组）。再灌注末留取缺血中心区、缺血边缘区和非缺血区心肌组织标本，应用Tunel染色法检测心肌细胞凋亡指数（apoptotic index, AI），应用实时定量PCR技术检测心肌细胞凋亡相关基因Bcl-2 mRNA和Bax mRNA表达，光学和电子显微镜观察缺血中心区心肌细胞形态。 结果 I/R组、RIP组、M组和M＋RIP组缺血中心区心肌细胞AI分别为（49.1±4.9）%、（34.2±2.9）%、（39.7±3.2）%和（29.0±4.9）%，缺血边缘区心肌细胞AI分别为（12.7±2.2）%、（8.2±1.6）%、（10.4±2.7）%和（5.9±1.4）%。在缺血中心区和缺血边缘区，M＋RIP组心肌细胞AI较I/R组和M组明显降低（P＜0.05），M＋RIP组的Bcl-2 mRNA表达较I/R组、RIP组和M组明显增强（P＜0.05），而M＋RIP组的Bax mRNA表达则较I/R组、RIP组和M组明显降低（P＜0.05），M＋RIP组的Bcl-2/Bax较I/R组、RIP组和M组明显升高（P＜0.05）。光学和电子显微镜检查显示，M＋RIP组的心肌形态和线粒体结构明显改善。 结论 Bcl-2相关信号通路的细胞凋亡抑制是联合应用吗啡和肢体RIP的心肌保护作用机制之一。

Objective To evaluate the role of anti-apoptosis in protection of combined morphine and limb remote ischemic postconditioning（RIP） against myocardial ischemia/reperfusion injury（I/RI）. Methods Sixty male SD rats were randomly allocated into four groups（n=15）： ischemia/reperfusion（I/R） group（group I/R）, group RIP, morphine group （group M）, and combined morphine and RIP group（group M＋RIP） . The apoptosis in the myocardial ischemic core, ischemic border and non-ischemic areas were assessed through the Tunel assay and real-time PCR for Bax mRNA and Bcl-2 mRNA. Optical and electronic microscopes were used to determine the cardiomyocyte morphology. Results The apoptotic index（AI） of myocytes in the ischemic core area was （49.1±4.9）%, （34.2±2.9）%, （39.7±3.2）% and （29.0±4.9）% in the I/R, RIP, M, M＋RIP groups, respectively. The AI of myocytes in the ischemic border area was（12.7±2.2）%, （8.2±1.6）%, （10.4±2.7）% and （5.9±1.4）% in the I/R, RIP, M, M＋RIP groups, respectively. In the ischemic core and border area, the AI of myocytes was significantly decreased in the M＋RIP group compared to that in the I/R and M groups（P〈0.05）, the expression of Bcl-2 mRNA was significantly increased（P〈0.05） and expression of Bax mRNA was significantly decreased in group M＋RIP（P〈0.05）, compared to that in the I/R, RIP, and M groups. Bcl-2/Bax ratio was significantly increased in group M＋RIP（P〈0.05）, compared to that in the I/R, RIP, and M groups. Optical and electronic microscopes showed that myocardial morphology and mitochondrial structures were significantly improved in group M＋RIP. Conclusions Apoptotic inhibition by Bcl-2 linked signaling pathway is one of the mechanisms of cardioprotection by combining morphine and limb RIP against I/RI.