参麦注射液对肠缺血/再灌注肺损伤大鼠肺组织p38MAPK及凋亡相关基因表达的影响

目的:观察参麦注射液(SM)对肠缺血/再灌注(I/R)肺损伤大鼠肺组织p38MAPK和凋亡相关基因Bax、Bcl-2蛋白表达的影响,探讨其保护机制。方法:采用夹闭肠系膜上动脉(SMA)方法建立大鼠肠I/R损伤模型。24只SD大鼠随机分为对照组(Control组)、肠缺血/再灌注组(I/R组)、参麦注射液组(SM+I/R组),每组8只。比较各组大鼠肺湿/干比(W/D)、肺表面活性物质主要成分卵磷脂(PC)及总磷脂(TPL)含量的变化;同时免疫组织化学法检测各组大鼠肺组织中p38MAPK、Bax及Bcl-2蛋白的表达水平。结果:与对照组比较,I/R组肺组织W/D明显升高,而PC和TPL的含量显著降低,肺组织p38MAPK、Bcl-2和Bax蛋白表达明显增强(P均＜0.01),其中Bax的增强比Bcl-2的增强更为明显,Bcl-2/Bax比值降低(P＜0.01);与I/R组比较,SM+I/R组大鼠肺组织W/D明显降低,PC和TPL的含量增加,肺组织p38MAPK和Bax蛋白表达下降(P均＜0.01),Bcl-2的表达增强,Bcl-2/Bax比值明显升高(P＜0.01)。相关分析显示,肠I/R时肺组织p38MAPK蛋白表达水平与肺表面活性物质主要功能成分PC含量及凋亡基因Bcl-2/Bax比值呈负相关(r分别为-0.787,-0.731,P均＜0.01)。结论:SM可能通过抑制p38MAPK信号通路的激活,提高Bcl-2/Bax比值来阻抑细胞凋亡,从而减轻肠I/R时的肺损伤。

Effects of Shenmai injection on the expression of p38MAPK and the apoptosis-related genes in lung injury induced by intestinal ischemia/reperfusion in rats

Objective:To observe the effects of Shenmai injection(SM) on p38MAPK and the apoptosis-related genes in lung injury induced by intestinal ischemia reperfusion (I/R) in rats and to investigate the protective mechanism of SM. Methods: Rat model of intestinal I/R injury was established with clamping of the superior mesenteric artery (SMA) for 60 min and then clamping was relieved for 60 min. Twenty-four SD rats were randomly divided into three groups with eight rats in each: control group, intestinal ischemia/reperfusion group(I/R group), Shenmai injection treated group (SM+I/R group). Lung wet/dry weight ratio(W/D), the contents of phosphatidylcholine (PC) and total phospholipid(TPL) which are the major ingredients of pulmonary surfactant were measured, as well as the expression levels of p38MAPK, Bcl-2 and Bax proteins in lung tissue were examined by using immunohistochemical method. Results: Compared with control group, lung W/D was significantly increased, the contents of PC and TPL were significantly decreased, the protein expression levels of p38MAPK, Bcl-2 and Bax were significantly increased in I/R group (all P＜0.01). But Bax protein expression was much greater than Bcl-2 protein expression, the ratio of Bcl-2 to Bax were significantly decreased in I/R group than that in control group (P＜0.01). Compared with I/R group, lung W/D was significantly decreased, while the contents of PC and TPL were significantly increased, the p38MAPK and Bax protein expression levels were significantly decreased in SM+I/R group (all P＜0.01); both Bcl-2 protein expression and the ratio of Bcl-2 to Bax were significantly increased in SM+I/R group than those in I/R group (P＜0.01). The correlation analysis indicated that the expression level of p38MAPK protein in lung tissue was negatively correlated with the contents of PC and the ratio of Bcl-2 to Bax (r is -0.787 and -0.731, all P＜0.01). Conclusion: SM can protect the lung injury induced by intestinal I/R injury, which may be mediated by inhibiting the activation of p38MAPK, improving the ratio of Bcl-2 to Bax to inhibit lung apoptosis.