Effect of enalapril on serum nitric oxide and expression of vascular endothelial growth factor in high pulmonary blood flow rats

Objective To explore the effect of ACEI on pulmonary hypertension and pulmonary vascular structural remodeling induced by high pulmonary flood flow in rats.Methods Twenty-three male SD rats were randomly divided into control group(C),shunting group(S),and shunting with enalapril group(SE).Abdominal aorta and inferior vena cava shunting were produced in groups S and SE.After 11-week shunting,mPAP of each rat was measured.RV/BW and RV/LV+S were documented.Pulmonary vascular microstructure was measured.WT% and WA% were calculated.Meanwhile,the concentration of plasma NO was measured.The expressions of VEGF by pulmonary arteries were semiquantitative.Results After 11-week aortocaval shunting,mPAP RV/BW and RV/LV+S were significantly increased in group S compared with those in group C.Muscularization of small pulmonary artery,WT% and WA% of pulmonary muscularized arteries were obviously increased in group S compared with those in group C.Meanwhile,plasma NO concentration was significantly decreased,VEGF protein expressions significantly increased in endothelial and smooth muscle cells of the pulmonary artery in group S than that in group C.However,mPAP,RV/BW and RV/LV+S were significantly decreased in group SE compared with those in group S.WT% and WA% of pulmonary muscularized arteries were obviously decreased in group SE compared with those in group S.Meanwhile,plasma NO concentration was significantly increased,VEGF protein expression reduced in endothelial cells of the pulmonary artery in group SE than that in group S.Conclusion Enalapril might ameliorate pulmonary hypertension and pulmonary vascular structure remodeling induced by high pulmonary blood flow.NO and VEGF might play important roles in the pathogenesis of it.