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(P<0.01),while lower in HP group than those of HH group(P<0.01).Differences of mCAP were not found among three groups(P>0.05);② UT(B_(max)) of HH group was higher than that of NC group(P<0.01),and lower in HP group than that of HH group(P<0.01).No difference existed among each group in the affinity to UⅡand concentration of UⅡ in plasma(P>0.05);③ Expression of UT mRNA in three grades of pulmonary arterioles were upregulated in HH group compared with NC group(respectively,P<0.01),while lower in HP group than HH group(respectively,P<0.05).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.