The Suppressing Effect of Valsartan and Spironolactone on Expression of Integrinβ_1 in Cardiac myocytes Spontaneously Hypertensive Rats

Objective To explore the surpressing effect of valsartan an d spironolactone on expression of integrin β\-1 in cardiac myocytes in spontaneously hypertensive rats. Methods Eighteen 6-week-old SHRs were randomly to receive valsartan (20 mg·kg -1 ·d -1 ) or spironolactone (10 mg·kg -1 ·d -1 ). 6 SHR and 6 WKY rats served as control. After 14 weeks, expression of integrin β 1 in cardiac myocytes were studied by immunohistochemistry. Results The ex pression of integrin β 1 were higher in SHR than in WKY group(P0 05). Losartan inhibit the expression of integrin β 1, while no change in integrin by spironolactone was found. Both valsartan and spironolactone decreased blood pressure, left vnticular mass to body weight ratio(LVM/BW) and the extent of cardiac fibrosis. Conclusion Although both valsartan and spironolactone decreased blood pressure, the inhibition effect on the integrin β\-1 in cardial myocytes was ma nifested only by valsartan treatment. Valsartan was more effective i n attenuating myocardial fibiosis than that by spironolactone. Integrin β 1 may play a role in hypertensive cardiac fibrosis.