川芎嗪减轻大鼠心肌缺血再灌注损伤后心肌细胞凋亡及其机制研究

An investigation on the effects of ligustrazine in attenuating apoptosis of myocardial ischemia reperfusion injury in rats and its mechanism

目的观察川芎嗪预处理对在体大鼠心肌缺血再灌注所致心肌细胞凋亡的影响,探讨其可能机制。方法 40只雄性SD大鼠随机分为假手术组、缺血再灌注组、川芎嗪组、川芎嗪+渥曼青霉素组和渥曼青霉素组。结扎左前降支35 min,再灌120 min建立缺血再灌注模型。假手术组前降支近端穿线但不结扎。用脱氧核糖核苷酸末端转移酶介导的原位缺口末端标记法(TUNEL)检测心肌细胞凋亡,酶联免疫吸附测定法测定缺血心肌组织半胱氨酸天冬氨酸蛋白酶3(caspase3)活性,实时荧光定量PCR法测定缺血心肌Bax和Bcl-2 mRNA的表达水平,Western blot法检测心肌磷酸化Akt的表达。结果缺血再灌注增加心肌细胞凋亡指数及caspase 3活性,川芎嗪预处理明显降低心肌细胞凋亡指数及caspase 3活性,降低Bax mRNA的表达水平,增加Bcl-2 mRNA和磷酸化Akt的表达水平,渥曼青霉素显著抑制上述指标的变化并取消了川芎嗪所致的磷酸化Akt表达水平的增加。结论川芎嗪能减轻在体大鼠心肌缺血再灌注所致心肌细胞凋亡,PI3K/Akt信号通路可能参与这一保护作用。

Objective To observe the effect of ligustrazine （tetramethylpyrazine, TMP） pretreatment on apoptosis caused by myocardial ischemia reperfusion （ IR） in rats in vivo and to investigate the possible mechanism. Methods Forty male Sprague-Dawley rats were randomly divided into sham, IR, TMP, TMP＋wortmannin （TMP＋wort） and wort group. All hearts except those in the sham group were subjected to 35 min ischemia followed by 120 min reperfusion. Apoptosis of myocardial cell was measured by TUNEL stai-ning and caspase-3 activity. The expression of Bax and Bcl-2 mRNA was detected by real time PCR. The expression of phosphorylated Akt and total Akt were detected by Western blot. Results Compared to the IR group, the myocardial tissues of the TMP group showed a decrease in the apoptosis index, caspase 3 activity and the expression of Bax mRNA. The expression of Bcl-2 mRNA and phosphoryla-tion Akt in the TMP group increased significantly compared to that in the IR group. However, these effects could be significantly re-versed by wortmannin which abolished the decrease of caspase 3, apoptosis index and Bax mRNA and increase of Bcl-2 mRNA and phosphorylation Akt brought by TMP. Conclusion Pretreatment of ligustrazine attenuated the apoptosis of myocardial IR in rats in vi-vo. PI3K/Akt pathway may be involved in the protective mechanism of ligustrazine.