诱导金属硫蛋白表达对大鼠体外心脏再灌注性心律失常的影响

Effects of induced metallothionein on reperfusion arrhythmia in rats

目的探讨金属硫蛋白表达对大鼠体外心脏再灌注性心律失常的影响。方法将32只SD大鼠随机分成实验组、对照组,每组16只。Western blot法检测金属硫蛋白的表达;测定心肌丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化酶(GSH-Px)水平,心肌细胞膜Na+-K+-ATP酶、Ca2+-Mg2+-ATP酶活性及冠状动脉流出液肌酸激酶同工酶(CK-MB)的漏出率。结果与对照组比较,实验组金属硫蛋白的表达增加;心室颤动及室性心动过速持续时间缩短,心律失常的积分减少;MDA降低,SOD、CAT、GSH-Px升高;Na+-K+-ATP酶、Ca2+-Mg2+-ATP酶增加,CK-MB的漏出率减少(P<0.01)。结论金属硫蛋白表达增加可减少大鼠再灌注性心律失常,其机制可能与金属硫蛋白稳定细胞膜、抑制脂质过氧化及钙超载有关。

Objective To investigate the effect of induced metallothionein （MT） expression on the reperfusion arrhythmia in rats and its possible mechanism. Methods Thirty-two Sprague-Dawley rats were divided randomly into the experiment and control groups. The reperfusion arrhythmia was observed after 60-minutes of reperfusion following 30-minute ischemia. The expression of MT in myocardium was examined using Western blot at reperfusion for 60 minutes. The levels of malonaldehyde（ MDA）, superoxide dismutase （ SOD）, catalase （ CAT）, glutathione peroxidase （GSH-Px） in myocardium and the activities of Na^＋-K^＋-ATPase, Ca^2＋ -Mg^2＋-ATPase on myocardial plasma membrane were determined. The levels of creatine kinase-MB（CK-MB） in coronary artery flow were also determined. Results Compared with control group, the durations of ventricular arrhythmia and ventricular tachycardia were reduced significantly in experiment group, the expressions of MT was significantly increased,the level of MDA was reduced significantly, the activities of SOD, CAT, GSH-Px, Na^＋ -K^＋-ATPase, Ca^2＋ -Mg^2＋ -ATPase were significantly increased, and CK-MB level was reduced. Conclusion The induced metallothionein expression markedly reduces the reperfusion ventricular arrhythmias in rats. The mechanism may be the stabilization of cell membrane,inhibition of lipid peroxidation and calcium overload by MT.