Effects of puerarin on urotensin II receptor in pulmonary arteries and right ventricle of chronic hypoxia-hypercapnia rats

Aim To investigate the effects of puerarin on the urotensin Ⅱ receptor(UT) in pulmonary arteries(arterials)and right ventricle of chronic hypoxia-hypercapnia rats.Methods Thirty male Sprague-Dawley rats were randomly divided into three groups,control group(NC),hypoxia-hypercapnia group(HH),hypoxia-hypercapnia+puerarin group(HP).Plasma UⅡ cocentration was measured with radio-immunity method.UⅡ receptor binding sites of pulmonary arteries sarcolemmaand myocardial sarcolemma were determined using radioligand assay.UT mRNA in various grades of pulmonary arterioles were measured by in situ hybridization.Results ① mPAP and RV/LV+S were much higher in HH group than those of NC group(P0.01),while lower in HP group than those of HH group(P0.01).Differences of mCAP were not found among three groups(P0.05);② UT(B_(max)) of HH group was higher than that of NC group(P0.01),and lower in HP group than that of HH group(P0.01).No difference existed among each group in the affinity to UⅡand concentration of UⅡ in plasma(P0.05);③ Expression of UT mRNA in three grades of pulmonary arterioles were upregulated in HH group compared with NC group(respectively,P0.01),while lower in HP group than HH group(respectively,P0.05).Conclusion Puerarin inhibits the expression of UT in pulmonary arteries and right ventricle,and improves pulmonary hypertension and right ventricular hypertrophy induced by chronic hypoxia-hypercapnia in rats.