Correlation between connective tissue growth factor and fibrosis of myocardium in spontaneously hypertensive rats and intervention with irbesartan

Objective To investigate the role of connective tissue growth factor(CTGF) in development of hypertensive myocardial fibrosis,and the mechanism of irbesartan to improve the hypertensive ventricular remodeling and myocardial fibrosis.Methods Twenty 12-week-old male spontaneously hypertensive rats(SHR) were randomly assigned to SHR group(n=10) and irbesartan group(n=10),10 twelveweek-old male Wistar Kyoto rats were used as control group(WKY group).Rats in irbesartan group was given a daily dose of 50 mg·kg~(-1) of irbesartan for 12 weeks by gavage and the other two groups were fed with a normal diet.TGF-β_1,CTGF were evaluated by qualitative and semiquantitative immunohistochemical staining and semiquantitative reverse transcription polymerase chain reaction.Masson staining was used in the study of total collagen in left ventricular interstitial tissue.Results Compared with the WKY group,the left ventricular weight index(LVI),collagen volume fraction(CVF),perivascular collagen area(PVCA),and the expression of TGF-β_1,CTGF and its mRNA in left ventricle were increased in SHR group(P0.05).Compared with the SHR group,these indexes decreased in irbesartan group obviously.(P0.05).Conclusions Hypertension induces the upregulation of connective tissue growth factor in the myocardium of rat.Treatment with irbesartan,an AngⅡ receptor antagonist,markedly decreases the enhanced CTGF expression.