倒卵叶五加总皂甙对大鼠心肌缺血再灌注损伤后 Bcl-2、Bax蛋白表达的影响

目的 探讨倒卵叶五加总皂甙(SAOH)对大鼠缺血心肌再灌注后Bcl—2和Bax蛋白表达的影响。方法 采用结扎左冠状动脉前降支30min，再灌注复制大鼠心肌缺血再灌注损伤(IRl)的模型，结扎前10min注射SAOH 50mg/kg、100mg/kg,测定心肌再灌注6h血浆乳酸脱氢酶(LDH)、磷酸肌酸激酶(CK)和一氧化氮(NO)、内皮素(ET)的含量，并用免疫组化的方法观察左室心肌Bcl—2和Bax蛋白的表达。结果 给予SAOH 50mg/kg、100mg/kg组较IRI组，能明显减少心肌酶的漏出(P＜0．01)，显著提高血浆NO含量(P＜0．01)，减少ET的生成(P＜0．01)，血浆NO与ET比值也明显升高(P＜0．01)；SAOH亦能减少心肌Bax蛋白、增加心肌Bcl—2蛋白的表达，Bax和Bcl—2的比值也随之下降。结论 SAOH有明显保护心肌的作用，其机制之一可能与其提高血浆NO含量、减少ET的生成，减少心肌细胞凋亡有关。

Effects of Saponin of Acanthopanax Obovatus Hoo on the Expression of Bcl-2 and Bax Proteins Following Myocardial Ischemia-Reperfusion Injury in Rats

Objective To study the effects of Saponin of Acanthopanax Obovatus Hoo (SAOH) on the expression of Bcl 2 and Bax proteins following myocardial ischemia reperfusion injury (IRI) in rats. Methods Ischemia reperfusion model was induced by left anterior descending coronary artery (LAD) ligation for 30 min, followed by 6 h of reperfusion. 10 min before LAD ligation, SAOH (50 mg/kg or 100 mg/kg) was administered by the route of sublingual vein injection. The level of lactate dehydrogenase (LDH), creatine kinase (CK) in myocardium, and the contents of nitric oxide (NO), endothelin (ET) in plasma were measured and the changes in the expression of Bcl 2 and Bax proteins in left ventricular myocardium after reperfusion were observed by immunohistochemical method. Results SAOH could markedly decrease the enzyme of myocardium leakage ( P <0 01), increase the content of NO in plasm ( P <0 01), reduce the level of ET ( P <0 01), and raise the ratio of NO to ET incidentally. Also, SAOH could obviously decrease the protein expression of Bax gene, but increase the protein expression of Bcl 2 gene. Conclusion SAOH could obviously protect myocardium during reperfusion injury, which might be associated with the increased content of NO, decreased level of ET in plasma, and reduced myocardial apoptosis.