The inhibiting effect of valsartan and spironolactone on cardiac fibrosis in spontaneously hypertensive rats

Objective To explore the inhibiting effect of valsartan and spironolactone on cardiac fibrosis and the expression of integrin β 1 and fibronectin in the heart of spontaneously hypertensive rats. Methods Eighteen 6 week old SHR were randomly divided into 3 groups with 6 in each: SHR control group, valsartan treating group(30 mg·kg -1 ·d -1 ) and spironolactone treating group ( 20 mg·kg -1 ·d -1 ). Six homogenous male WKY rats served as normal group. After 14 weeks of treatment, systolic blood pressure, left ventricular mass, the ratio of left ventricular mass to body weight (LVM/BW), collagen volume fraction(CVF) and perivascular collagen area(PVCA) were determined and compared among these groups. The expression of integrin β 1 and fibronectin were also examined by immunohistochemical method. Results Compared with the untreated SHR S, systolic blood pressure was significantly decreased in both treatment groups. LVM/BW〔(2 84±0 14)×10 -3 vs(3 22±0 15)×10 -3 〕, CVF〔(3 21±0 22)%vs(4 00±0 28)%〕, PVCA〔(0 62±0 15)%vs(0 94±0 56)%〕 were lower in both treatment groups, these parameters in SHR V group were even lower than those in SHR S group. Compared with the untreated SHR S, the expression of integrin β 1 was significantly reduced in SHR V group, while the expression of fibronectin was markedly reduced in both treatment groups. Conclusions Both valsartan and spironolactone could control blood pressure, and effectively inhibit the cardiac fibrosis. Valsartan could also inhibit the expression of cardiac integrin β 1 and fibronectin, which might be the reason that valsartan is better than spironolactone in inhibiting cardiac fibrosis.