滋膵通脉饮对糖尿病心肌病大鼠心肌纤维化和转化生长因子β1/Smads信号通路的影响

Effect of Zicuitongmai Yin on Myocardial Fibrosis and TGF-β1/Smads Signaling Pathway in Diabetic Cardiomyopathy Rats

目的探讨滋膵通脉饮对糖尿病心肌病大鼠转化生长因子(TGF)-β1/Smads3信号通路的影响。方法将SD大鼠随机分为空白对照组,模型组,滋膵通脉饮高、低剂量组(17.6 g·kg^-1,8.8 g·kg^-1)和依那普利组(0.53 mg·kg^-1),空白对照组予以腹腔注射等量柠檬酸-柠檬酸三钠缓冲液,余组大鼠采用高脂高糖饲料喂养+单次腹腔注射链脲佐菌素的方法构建2型糖尿病大鼠模型。造模结束后,模型组和空白对照组灌服同等容积的蒸馏水,余组分别给与药物干预,共干预4周。4周后观察心脏指数和左室指数,PCR技术检测大鼠心肌组织转化生长因子(TGF)-β1 mRNA、Smads3 mRNA和Smads7 mRNA的表达,蛋白印迹法检测心肌组织TGF-β1、Smads3、Smads7的蛋白表达。Masson染色观察大鼠心肌结构的改变,计算胶原容积分数。结果与空白对照组比较,模型组心脏指数和左室指数明显升高(P<0.01);与模型组比较,滋膵通脉饮高剂量组、滋膵通脉饮低剂量组和依那普利组心脏指数和左室指数明显降低(P<0.05,P<0.01);与空白对照组比较,模型组大鼠TGF-β1 mRNA、Smads3 mRNA和TGF-β1、Smads3蛋白表达明显升高(P<0.01);与模型组比较,滋膵通脉饮高剂量组、滋膵通脉饮低剂量组和依那普利组TGF-β1 mRNA、Smads3 mRNA和TGF-β1、Smads3蛋白表达明显降低(P<0.01);与空白对照组比较,模型组大鼠Smads7 mRNA和Smads7蛋白表达明显降低(P<0.01);与模型组比较,滋膵通脉饮高剂量组、滋膵通脉饮低剂量组和依那普利组Smads7 mRNA和Smads7蛋白表达明显升高(P<0.05,P<0.01)。Masson染色结果显示:空白对照组大鼠肌纤维排列整齐,肌纤维连接完好。模型组大鼠心肌纤维排列紊乱,胶原纤维增多,可见纤维断裂。高剂量组大鼠肌纤维排列整齐,可见极少量胶原纤维。低剂量组大鼠肌纤维排列稍紊乱。依那普利组可见极少量胶原纤维,肌纤维断裂不明显。与空白对照组比较,模型组大鼠胶原容积分数明显升高(P<0.01);与模型组比较,滋膵通脉饮高剂量组、滋膵通脉饮低剂量组和依那普利组胶原容积分数明显降低(P<0.01)。结论滋膵通脉饮能抑制糖尿病心肌病大鼠心肌纤维化,改善心肌重构,其作用可能与调节TGF-β1/Smads信号通路有关。

Objective To explore the effect of Zicuitongmai Yin on TGF-β1/Smads signal pathway in diabetic cardiomyopathy rats.MethodsSD rats were randomly divided into blank control group,model group,high and low dose group(17.6 g·kg^-1,8.8 g·kg^-1)and enalapril group(0.53 mg·kg^-1). The blank control group was given the same amount of citric acid-trisodium citrate buffer by intraperitoneal injection,and high fat and high sugar diet plus a single intraperitoneal injection of streptozotocin were used to build the model of type 2 diabetic rats. After the type 2 diabetic model was established,the model group and the blank control group were given the same volume of distilled water, and the other groups were given drug intervention for 4 weeks. 4 weeks later, the cardiac index and left ventricular index were observed. The expression of TGF-β1 mRNA, Smads3 mRNA and Smads7 mRNA were detected by PCR, and the protein expression of TGF-β1, Smads3 and Smads7 were detected by Western blot.Changes of myocardial structure in rats were observed by Masson staining and the collagen volume fraction was calculated.ResultsThe heart index and left ventricular index in the model group were significantly higher compared with those in the blank control group(P<0.01);the heart index and left ventricular index of high dose group,low dose group and enalapril group were significantly lower compared with those in the model group(P<0.05, P<0.01);the expression of TGF-β1 mRNA, Smads3 mRNA, TGF-β1 and Smads3 protein in the model group increased significantly compared with those in the blank control group(P<0.01);the expression of TGF-β1 mRNA, Smads3 mRNA, TGF-β1, and Smads3 protein in the high dose group, the low dose group and the enalapril group decreased significantly compared with those in the model group(P<0.01). The expression of Smads7 mRNA and Smads7 protein in the model group decreased significantly compared with those in the blank control group(P<0.01);the expression of Smads7 mRNA and Smads7 protein in high dose group,low dose group and enalapril group increased significantly compared with those in the model group(P<0.05, P<0.01). The results of Masson staining showed that the muscle fibers of blank control group were arranged in order and closely connected. In the model group, the disorderly arrangement of myocardial fibers, the increase of collagen fibers and fiber breakage were observed. The orderly arrangement of muscle fibers and small amount of collagen fibers could be seen in high dose group. The arrangement of muscle fibers was slightly disordered in the low dose group. Few collagen fibers and slight fiber breakage were found in enalapril group. The collagen volume fraction of the model group was significantly increased compared with that in the blank control group(P<0.01);The collagen volume fraction in the high dose group,low dose and enalapril group was significantly decreased compared with that in the model group(P<0.01).Conclusion Zicuitongmai Yincan inhibit myocardial fibrosis and improve the myocardial remodeling of diabetic cardiomyopathy rats,which may be related to the regulation of TGF-β1/Smads signal pathway.