RESUMO
Objective To study the effect of chloride channel blocker(niflumic acid,NFA) on pulmonary hypertension induced by high pulmonary blood flow in rats.Methods Fifty male or female Sprague-Dawley rats were randomly divided into 5 groups:normal group,sham group,model group,drug 1 group,and drug 2 group,with 10 rats in each group.After subjected to an abdominal aorta-inferior vena cava shunt,all the rats were reared under the same condition for 11 weeks.Then,mean pulmonary artery pressure(mPAP) and right ventricular hypertrophy index(RVHI) of each rat were measured.In addition,arterial wall area/vessel area (W/V) and arterial wall thickness/vessel external diameter(T/D) of each rat were also measured.Results 1.The mPAP of model group [(25.79 ± 4.03) mmHg,1 mmHg =0.133 kPa] was significantly higher than those of normal group [(16.48 ± 1.70) mmHg],sham group [(17.03 ± 2.01) mmHg],drug 1 group [(21.78 ± 2.77) mmHg] and drug 2 group [(20.31 ± 2.15) mmHg] (F =18.983,P ＜0.01).Although the mPAP of drug 1 group was a little higher than drug 2 group,there was no significant difference (P ＞ 0.05).Compared with normal group and sham group,the mPAP of drug 1 group and drug 2 group increased(P ＜0.01,respectively).2.The W/V and T/D of model group were significantly higher than those of normal group,sham group,drug 1 group and drug 2 group (F =26.135,15.527,all P ＜ 0.001).The W/V and T/D of two drug groups showed no significant difference,but they were higher than those of normal group and sham group (P ＜ 0.01,respectively).Conclusions Chloride channel blocker NFA partly decrease mPAP of pulmonary hypertension indnced by high pulmonary blood flow in rats,and inhibit proliferation of vascular smooth muscle cells.These results suggest that NFA had part of therapeutic effect to pulmonary hypertension induced by high pulmonary blood flow.