硫化氢对急性缺血所致心肌细胞凋亡的影响

Effects of hydrogen sulfide on cardiomyocyte apoptosis induced by acute myocardial ischemia in rats

目的观察H2S对急性缺血所致大鼠心肌细胞凋亡的影响。方法健康成年♂SD大鼠(270±20)g,随机分为:假手术组、缺血组、缺血+NaHS低、中、高剂量组。麻醉大鼠,结扎左冠状动脉前降支,NaHS低、中、高剂量组分别于缺血3 h时腹腔注射0.78、1.56和3.12 mg·kg-1的NaHS,缺血组注射等容量的生理盐水,假手术组只穿线不结扎。各组大鼠均于缺血6 h时经颈总动脉取血迅速开胸取心脏,流式细胞术检测心肌组织细胞凋亡率,Western blot法检测caspase-3蛋白的表达,免疫组化法检测Bcl-2和Bax蛋白的表达,HE染色观察心肌组织学变化。结果大鼠心肌缺血6 h后,心肌细胞凋亡率、caspase-3和Bax表达阳性细胞数百分率明显升高,Bcl-2表达阳性细胞数百分率降低。缺血3 h治疗3 h时,NaHS 3个剂量组大鼠心肌细胞凋亡率、caspase-3和Bax表达阳性细胞数百分率明显低于缺血组,Bcl-2蛋白表达、Bcl-2/Bax比值高于缺血组。组织形态学变化显示,假手术组大鼠心肌细胞排列整齐,着色均匀,缺血组大鼠心脏部分区域心肌纤维横纹不齐或消失,核偏移甚至裂解消失,有炎性因子渗出,NaHS 3个剂量组大鼠心肌细胞损伤程度较缺血组明显减轻。结论硫化氢对大鼠急性缺血心肌具有一定的保护作用,上调Bcl-2的表达,下调Bax表达,抑制细胞凋亡可能是其重要保护作用机制。

Aim To investigate the effect of hydrogen sulfide （H2S） on cardiomyocyte apoptosis in rats with acute myocardial ischemia and to analyze the pathologi- cal damage of myocardial tissue. Methods Forty male rats were randomly divided into five groups： sham group, ischemia group, ischemia ＋ NariS （Low dose） group, ischemia ＋ NariS （Middle dose） group, ische- mia ＋ Nails （High dose） group. The acute myocardial ischemia model was established by ligating the left an- terior descending coronary （LAD） of the rats. LADs were not ligated but only threaded in the sham opera-tion rats. In ischemia ＋ NariS Low, Middle and High dose groups the NariS （0. 78, 1.56, 3.12 mg~ kg-~ ） were intraperitoneally administrated respectively 3 hours after ischemia. The rats were respectively killed 6 hours after ischemia. Hearts were quickly removed, and the apoptotic rate of cardiomyocytes was evaluated by Flow Cytometry. The positive expressions of Bcl-2 and Bax in cardiomyocytes were respectively detected by immunohistochemistry. The expression of caspase-3 protein was observed with Western blot analysis. Re- suits Acute myocardial ischemia significantly increased the apoptotic rate of cardiomyocytes and the expression of Bax and caspase-3 protein, and decreased the expression of bcl-2 and the ratio of bcl-2/Bax. Ad- ministration of Naris reduced the percentage of apop- totic cells, the expression of caspase-3 and Bax pro- tein, improved the expression of bcl-2 protein, the ra- tio of bcl-2/Bax, and the pathological injury of the my- ocardial cells induced by acute ischemia in rats. Con-clusion H2S attenuates acute ischemia induced-apop- tosis of myocardial cells, whose mechanisms may be involved in the increases in the expression of Bcl-2 and the ratio of bcl-2/Bax and the decreases in the expres- sions Bax and Cleaved capsase-3.