Influence of oxygen therapy on pulmonary vessel remodeling and plasma ET-1 level in rats with pulmonary hypertension induced by chronic hypoxia-hypercapnia

Objective:To investigate the role of oxygen therapy on pulmonary vascular remodeling and plasma ET 1 level in rats with chronic hypoxia and hypercapnia induced pulmonary hypertension.Methods:Changes in mean pulmonary artery pressure(mPAP),weight ratio of right ventricle to left ventride and septum(RV/LV+S),pulmonary arterial microscopy and plasma ET 1 were observed. Forty male Sprague Dawley rats were randomly divided into four groups:normal control group(NC),groups of only 2 week hypoxia hypercapnia(HH),2 week hypoxia hypercapnia and 3 week oxygen therapy(HO) and 2 week hypoxia hypercapnia and 3 week air inhalation(HC),hypoxia after 4 week.Results:①mPAP and RV/LV+S of HH group were higher than those of NC group(P0.01). In HO group,mPAP and RV/LV+S were lower(P0.05) than those in HC group.②Level of plasma ET 1 in HH group was significantly higher than that in NC group(P0.01),but the level of plasma ET 1 of HO group was lower than that of HC group.③Light microscopy showed that vessel well area/total area(WA/TA),and media thickness of pulmonary arterioles were much higher in rats of HH group and vessel cavity area/total area(EA/TA) was lower in HH group than those in NC group(P0.01). WA/TA,EA/TA and mMTPA in HO group were obviously improved.Conclusion:Oxygen therapy may have great effect on pulmonary artery pressure and plasma ET 1 level. It can obviously decrease the pulmonary arterial remodeling.