Effect Of Pinacidil On Myocardial Remodeling In Pressure Overload Heart Failure Rat Model

Objective To investigate the effects of pinacidil on heart function and myocardial remodeling in pressure overload heart failure rats.Methods Pressure overload heart failure model was established by abdominal aortic constriction.40 male Wistar rats were randomized into 3 groups:sham-operated group(F),aortic-banded group(T) and Pinacidil group(M).Rats in M group received Pinacidil 2mg·kg-1·d-1 at the 4th week after operation.Hemodynamic parameters such as systolic blood pressure(SBP),diastolic blood pressure(DBP),maximal rising and falling velocity of left intraventricular pressure(±dp/dtmax) and left ventricular end-diastolic pressure(LVEDP) were measured at the 12th week after operation.Serum brain natriuretic peptide(BNP) levels,collagen type I and aminotermianl peptide of type Ⅲ procollagen were tested with ELISA kit.After the rats were sacrificed,the mass indexes of hearts(MI) were calculated(heart mass/body weight).Myocardial fibre diameters were measured with HE staining.Results ①Compared with F group,MI and the diameters of myocardial fibre in T group were increased dramatically.Pinacidil markedly decreased the above two indexes.②SBP,DBP and LVEDP were higher in T group than F group,and was lower in M group.±dp/dtmax were lower in T group(P<0.01).Serum BNP levels increased significantly in T group.Even though Pinacidil dramatically decreased the BNP level,it still higher than F group(P<0.01).③The serum levels of collagen type I and PⅢNP were both increased significantly in T group as compared with F group(P<0.05).Pinacidil dramatically decrease the above two parameters(P<0.01).Conclusion Pinacidil can improve the myocardial hypertrophy and fibrosis after abdominal aortic constriction,and delay the progression of heart failure.