Expression of nitrotryrosine in lung tissues of hypoxic rats

Objective To study the expression of nitrotryrosine in the lung tissues of hypoxic rats and to explore the relationship between oxidative stress and hypoxic pulmonary hypertension(HPH).Methods Fourteen Wistar rats were randomly divided into two groups:control group,hypoxic group.The animal model of pulmonary hypertension was established by exposing the rats to normabaric hypoxic conditions for three weeks.Mean pulmonary arterial pressure(mPAP)and right ventricle hypertrophy index(RVHI)were measured.The indices of wall thickness of pulmonary arteriole(wall thickness,WT% and wall area,WA%)were measured by a computerized image analyzer.The expression of nitrotryrosine in pulmonary arterioles 1.07)% in hypoxic group were significantly higher than those in control group[(16.67±0.97)mm Hg,6.51)%;in control group,WT% was(14.19±2.61)%and WA% was(46.67±7.42)%,the diference was group was significantly elevated,compared with control group(1.00±0.00)(P<0.01).There was no significantly difference in NT expression of distal pulmonary arterioles between two groups.Positive correlation was demonstrated between NT expression and mPAP in hypoxic group.Conclusions NT expression is elevated in rats with HPH,by a mechanism presumably involving oxidative stress. Key words: Hypoxia pulmonary hypertension; Nitrotyrosine; Oxidative stress