Prevention of myocardial hypertrophy in pressure overload rats by Lisinopril and Losartan

Objective To investigate the structural and biochemical change of cardiovascular remodeling and examine the preventive effects of Losartan and Lisinopril in pressure overload rats.Methods Pressure overload model was produced by abdominal aortic coarctation in rats.Measurements were done for the mean arterial pressure(MAP),the change of myocardial hypertrophy,nitric oxide(NO),nitric oxide synthase(NOS)and collagen protein of local myocardium in six groups including Group Sham,Group Model,hypotensive and sub-hypotensive dose groups Lisinopril and Losartan.Lisinopril and Losartan had been given by daily gavage for thirty days since the first day after operation.Results Compare with Group Sham,MAP,left ventricular weights(LVW),left ventricular mass index(LVMI),transverse diameter myocytes(TDM)and collagen protein in Group Model increased respectively 28.6%,20.5%,26.9%,17.9% and 54.4%(P0.01) while NO and NOS decreased by 53.4% and 51.2%(P0.01).Hypotensive dose Lisinopril,Losartan and sub-hypotensive dose Losartan could prevent cardiovascular remodeling and increase NO and NOS completely.Sub-hypotensive dose Lisinopril was able to lighten myocardial hypertrophy,but it significantly differed from Group Sham(P0.01),while NO and NOS didn't improve.LVMI was positively related to MAP and collagen protein respectively(r=0.7841,r=0.8177,P0.01)while it was negatively related to NO(r=0.7730,P0.01).Conclusions Cardiovascular remodeling had intimate connection with MAP,NO and collagen protein;The effect of Lisinopril on myocardial hypertrophy might be common action of hemodynamic stress and non-hemodynamic stress factors while the effect of Losartan could rely on non-hemodynamic stress factors.