2011•Jiefangjun yixue zazhiRequires access
Effects of telmisartan on the expression of NADPH oxidase subunits in the myocardium of type 2 diabetic rats
Guo Zhi-xi
Open publisher page 0 citations
Abstract
Objective To explore the effect of telmisartan on the expression of NADPH oxidase subunits p22phox and NOX4 in the myocardiam of type 2 diabetic rats.Methods Thirty-six male Wistar rats were randomly divided into two groups: normal control group(group A,n=10),diabetic model group(n=26).Type 2 diabetic model was established by high-fat and high-sugar diet followed by intraperitoneal injection of a low dose of streptozotocin(STZ).After the model was reproduced successfully,20 diabetic rats were randomly divided into diabetic subgroup(group B,n=10) and telmisartan-treated subgroup(group C,n=10).Rats in group C were orally administered telmisartan(5mg/kg/d),and rats in group A and B were given equivalent volume of normal saline.All rats were sacrificed 12 weeks after treatment.The mRNA expressions of myocardial p22phox and NOX4 were detected by real-time fluorescence quantitative PCR,and the protein expressions of myocardial connective tissue growth factor(CTGF) and copper-zinc-superoxide dismutase(Cu-Zn-SOD) were detected by immunohistochemical staining.Results Compared with group A,the ratio of heart/body weight,the mRNA expression of myocardial p22phox and NOX4,and the protein expression of myocardial CTGF increased significantly in group B,and the protein expression of myocardial Cu-Zn-SOD decreased significantly(P0.05).The ratio of heart/body weight,the mRNA expression of myocardial p22phox and NOX4,and the protein expression of myocardial CTGF decreased significantly in group C than in group B(P0.05),and the protein expression of myocardial Cu-Zn-SOD increased significantly in group C when compared with that of group B(P0.05),but no significant difference of the above indexes was found between group A and C(P0.05).Conclusions Telmisartan can down-regulate the over-expression of myocardial NOX4 and p22phox mRNA in type 2 diabetic rats,lessen the myocardial damage induced by oxidative stress,thus plays a protective role in the myocardium of diabetic rats.