黄芪桂枝五物汤对糖尿病大鼠心肌梗死后心肌重塑及TGF-β_(1)/Smad3通路的影响

Effects of Huangqi Guizhi Wuwu Decoction on myocardial remodeling and TGF-β_(1)/Smad3 pathway after myocardial infarction in diabetic rats

目的研究黄芪桂枝五物汤对糖尿病大鼠心肌梗死后心肌重塑和转化生长因子-β_(1)(TGF-β_(1))/Smad3通路的影响。方法雄性SD大鼠72只,随机取12只作为空白组,其余大鼠采用高糖高脂饲料喂养建立糖尿病模型,然后采用冠状动脉结扎法建立心肌梗死模型。将50只造模成功大鼠随机分为模型组、福辛普利组及黄芪桂枝五物汤低、中、高剂量组,每组10只。黄芪桂枝五物汤低、中、高剂量组分别给予黄芪桂枝五物汤2.5 g/kg、5 g/kg、10 g/kg灌胃,福辛普利组给予福辛普利4 mg/kg灌胃,空白组及模型组给予生理盐水灌胃,均1次/d,连续8周。超声诊断仪测定大鼠左心室短轴缩短率(LVFS)及左心室射血分数(LVEF),全自动生化分析仪测定血清肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)、脑钠肽(BNP)、血糖及糖化血红蛋白水平,ELISA法测定心肌组织中一氧化氮(NO)、内皮型一氧化氮合酶(eNOS)、丙二醛(MDA)及内皮素(ET)含量,HE染色观察心肌组织病理形态,Western blot法测定心肌组织中TGF-β_(1)及Smad3蛋白表达情况,RT-PCR法测定心肌组织中TGF-β_(1)mRNA表达量。结果与空白组比较,模型组大鼠LVFS及LVEF、心肌组织中NO和eNOS含量均明显降低(P均<0.05),血清CK、CK-MB、BNP、血糖、糖化血红蛋白水平及心肌组织中MDA和ET含量、心肌组织中TGF-β_(1)和p-Smad3/Smad3蛋白相对表达量、心肌组织中TGF-β_(1)mRNA相对表达量均明显升高(P均<0.05),大鼠心肌组织有明显炎症浸润及坏死;与模型组比较,黄芪桂枝五物汤各组及福辛普利组大鼠LVFS及LVEF、心肌组织中NO和eNOS含量均明显升高(P均<0.05),血清CK、CK-MB、BNP、血糖、糖化血红蛋白水平及心肌组织中MDA和ET含量、心肌组织中TGF-β_(1)和p-Smad3/Smad3蛋白相对表达量、心肌组织中TGF-β_(1)mRNA相对表达量均明降低(P均<0.05),大鼠心肌组织炎症坏死明显减轻。结论黄芪桂枝五物汤能够显著改善糖尿病心肌梗死大鼠心功能,抑制心肌重塑,调节血糖水平,其机制可能与调节TGF-β_(1)/Smad3通路有关。

Objective It is to study the repairing effect of Huangqi Guizhi Wuwu Decoction on myocardial remodeling after myocardial infarction in diabetic rats and its effect on transforming growth factor-β_(1)(TGF-β_(1))/Smad pathway.Methods Seventy-two male SD rats were selected,in which 12 ones were randomly selected as blank group,the remain rats were fed with high-sugar and high-fat diet to establish diabetic models,and then to establish myocardial infarction models by coronary artery ligation.50 successfully modeled rats were randomly divided into model group,fosinopril group,and Huangqi Guizhi Wuwu Decoction low,medium,and high dose groups,with 10 rats in each group.The Huangqi Guizhi Wuwu Decoction low,medium and high dose groups were given Huangqi Guizhi Wuwu Decoction 2.5 g/kg,5 g/kg and 10 g/kg by gavage,respectively,the fosinopril group was given fosinopril 4 mg/kg by gavage,and the blank group and model group were given normal saline by gavage,once daily,continuously treated for 8 weeks.The left ventricular fraction shortening(LVFS)and left ventricular ejection fraction(LVEF)of the rat were measured by ultrasonic diagnostic instrument,the levels of serum creatine kinase(CK),creatine kinase isoenzyme(CK-MB),brain natriuretic peptide(BNP),blood glucose and glycosylated hemoglobin were measured by automatic biochemical analyzer,the contents of NO,endothelial nitric oxide synthase(NOS),malondialdehyde(MDA)and endothelin(ET)in myocardial tissue were detected by ELISA,the pathological changes of myocardial tissue was observed by HE staining,the expressions of TGF-β_(1)and Smad3 protein in myocardial tissues were determined by Western blot,and the expression of TGF-β_(1)mRNA in myocardial tissues was determined by RT-PCR.Results Compared with the blank group,LVFS and LVEF,the contents of NO and eNOS in myocardial tissues of rats in the model group were significantly decreased(all P<0.05),the levels of serum CK,CK-MB,BNP,blood glucose,glycosylated hemoglobin and the contents of MDA and ET in myocardial tissues,the relative expressions of TGF-β_(1)and p-Smad3/Smad3 proteins in myocardial tissues,the relative expression of TGF-β_(1)mRNA in myocardial tissues were all significantly increased(all P<0.05),obvious inflammatory infiltration and necrosis in myocardial tissues of the rats were found.Compared with the model group,LVFS and LVEF,the contents of NO and eNOS in myocardial tissues of rats in the fosinopril group,and Huangqi Guizhi Wuwu Decoction low,medium,and high dose groups were significantly increased(all P<0.05),the levels of serum CK,CK-MB,BNP,blood glucose,glycosylated hemoglobin and the contents of MDA and ET in myocardial tissues,the relative expressions of TGF-β_(1)and p-Smad3/Smad3 proteins in myocardial tissues,the relative expression of TGF-β_(1)mRNA in myocardial tissues were all significantly decreased(all P<0.05),obvious inflammatory infiltration and necrosis in myocardial tissues of the rats were obviously alleviated.Conclusion Huangqi Guizhi Wuwu Decoction can significantly improve cardiac function,inhibit myocardial tissue damage,and regulate blood glucose levels in diabetic myocardial infarction rats.The mechanism may be related to the regulation of TGF-β_(1)/Smad pathway.