Prevent and reverse effects of sildenafil on pulmonary hypertension in pneumonectomy combining to monocrotaline treated rats

Objective To investigate the protective and reverse effects of sildenafil on pulmonary hypertension in pneumonectomy combining to monocrotaline treated rats.Method The SD rats were randomly divided into the shamed-operation group,the control group and the treament group.All the rats were treated with monocrotaline(60mg·kg~(-1)) one week after pneumonectomy.The treament group was treated with sidenafil((1.7 mg·)(kg~(-1)·d~(-1))) for 3 weeks.The mean pulmonary arterial pressure(mPAP) and right ventricle/left ventricle and septum were measured and the small pulmonary arterial morphologic changes were observed with morphmetric analysis under microscopes.Immunohistochemistry was used to determine the expression of endothelin-1 A type receptor(ET_A-R) on small pumlonary arterial and radioimmunity was used to determine the ET-1 level in plasma.Results The mPAP,,small pumlonary arterial morphologic changes were highly improved in sildenafil group(P0.05).The expression of ET_A-R on small pumlonary arterial was significently reduced in treament group(P0.05).The ET-1 level in plasma was increased in treament group,but not reach the significant.Conclusion Sildenafil can prevent and reverse the development of pulmonary hypertension in pneumonectomy combining to monocrotaline treated rats.