钙网蛋白在不同预处理心肌细胞缺血再灌注的保护作用

目的 观察3种不同预处理对在体缺血再灌注心肌的保护作用,探讨钙网蛋白(CRT)在预处理心肌细胞缺血再灌注损伤的作用.方法 将30只成年SD大鼠随机分成5组(n=6),分别为缺血再灌注组、缺血预处理组、腺苷预处理组、远程预处理组和假手术组.建立大鼠在体缺血冉灌注损伤模型,观察各组缺血再灌注前后心功能变化,并检测再灌注末血清肌钙蛋白T(cTnT)、丙二醛(MDA)、超氧化物歧化酶(SOD)的变化以及心肌组织CRT的表达.结果 缺血预处理组、远程预处理组与缺血再灌注组比较(±dp/dt max)有明显提高(P<0.05).缺血预处理组、腺苷预处理组、远程预处理组cTnT、MDA值均低于缺血再灌注组,SOD值高于缺血再灌注组(P<0.05);腺苷预处理组SOD值高于缺血预处理组和远程预处理组,cTnT值则低于后2组(P<0.05);缺血预处理组、腺苷预处理组、远程组与缺血再灌注组比较,CRT表达灰度值均显著降低(P<0.05).结论 腺苷预处理、远程预处理均可以模拟缺血预处理的心肌保护作用;预处理可能通过下调钙网蛋白高表达减轻在体大鼠心肌细胞缺血再灌注损伤.

The role of calreticulin in three different kinds of preconditioning against myocardial ischemia/reperfusion injury in rats

Objective To evaluate the role of calreticulin (CRT) in myocardial protection of three different kinds of preconditioning against myocardial ischemia/reperfusion injury. Methods Thirty SD rats were randomly divided into 5 groups:ischemia reperfusion group (IR), ischemia preconditioning group(IP), adenosine preconditioning group (AP), remote preconditioning group(RP), and sham-opera-tion group (blank control). The ischemia/reperfusion model was established in vivo. Hemodynamic chan-ges of heart function were observed,and serum cardiac Troponin T (cTnT), superoxide dismutase (SOD), malondialdehyde (MDA) and the expression of CRT in myocardium were detected. Results ±dp/dt max,serum cTnT and MDA,and the expression of CRT in RP, AP and IP groups were significantly lower than those in IR group, also SOD level in these three groups was higher than in IR group (P<0.05). AP group had a higher SOD level venous IP and RP groups (P<0.05),also cTnT in AP group was lower than in IP and RP groups (P<0.05). Conclusion Remote preconditioning may mimic the protective effect of ischemic preconditioning. Remote preconditioning attenuated myocardial ischemia/reperfusion injury in vi-vo possibly through down-regulating the CRT expression in rats.