Abstract: AIM: To investigate the expression of connective tissue growth factor (CTGF) in the myocardium of spontaneously hypertensive rats and the relationship of the hypertensive ventricular remodeling, myocardial fibrosis and whether irbesartan alter this expression.METHODS: 20 twenty-week-old male spontaneously hypertensive rats were randomly assigned to SHR group and irbesartan group (n =10 in each), and 10 twenty-weekold male Wistar Kyoto rats were considered as WKY group.Rats in irbesartan group were given a daily dose of 50 mg·kg^-1 irbesartan for 12 weeks by gavage and the other two groups were fed with a normal diet.TGF-β1 and CTGF were evaluated by qualitative and semiquantitative immunohistochemical staining and semiquantitative reverse transcription polymerase chain reaction.MASSON staining were used in the study of total collagen in left ventricular interstitial tissue.RESULTS: Compared with the WKY group, the left ventricular wight index (LVI), collagen volume fraction (CVF), perivascular collagen area (PVCA) and the expression of TGF-β1, CTGF and its mRNA in left ventricular increased in SHR group (P < 0.05).Compared with the SHR group, these indexes obviously decreased in irbesartan group (P < 0.05).CONCLUSION: Hypertension induces the upregulation of connective tissue growth factor in the myocardium of rat.Treatment with irbesartan, an AngII receptor antagon markedly decreases the enhanced CTGF expression.This may reflect a new mechanism of AngII receptor antagon on preventing left ventricular remodeling and myocardial fibrosis.

Key words: CTGF, spontaneously hypertensive rats, irbesartan, ventricular remodeling, myocardial fibrosis