过氧化物酶增殖体激活受体α在急性肺损伤大鼠肺组织的表达及其意义

Expression of peroxisome proliferation activated receptor-α in lung of rats with acute lung injury induced by lipopolysaccharide

目的:观察内毒素(LPS)复制的急性肺损伤(ALI)大鼠肺组织过氧化物酶增殖体激活受体α(PPARα)表达的变化,探讨PPARα在ALI中可能的作用。方法:将40只雄性Wistar大鼠随机分为对照组、LPS致伤1h组、2h组、4h组和8h组。用LPS(5mg/kg)静脉注射复制大鼠ALI模型,分别在LPS致伤后1h、2h、4h、8h时处死大鼠,测定各组肺组织湿/干重比(W/D)及肺组织病理变化;采用RT-PCR法检测肺组织中PPARα mRNA的表达;采用免疫组化法检测肺组织中PPARα的表达。结果:LPS致伤后2h、4h、8h肺组织W/D均显著高于对照组(均P<0.01);LPS致伤后2h、4hPPARαmRNA表达分别显著低于对照组(均P<0.01);而LPS致伤4h和8h组PPARα表达阳性细胞数显著低于对照组(均P<0.05)。结论:PPARα在ALI大鼠肺组织表达降低。表明PPARα在急性肺损伤的发病机制中具有重要作用。

AIM： To investigate the expression and role of PPARα in lung of rats stimulated with lipepelysaccharide （LPS）. METHODS： 40 male Wistar rats were divided randomly into five groups： one group were injected with saline （control group）, others were killed 1 h, 2 h, 4 h and 8 h after LPS （5 mg/kg） injection, respectively （ 1 h group, 2 h group, 4 h group and 8 h group）. The ratio of lung wet - dry weight was measured. Semi - quantitative reverse transcription pelymerase chain reaction （ RT - PCR） and immunohistochemical method were used to measure expression of PPARct mRNA and PPARα protein in the lung. RESULTS： The ratio of lung wet - dry weight in LPS 2h, 4h and 8h groups were significantly higher than those in control group （P 〈0. 01 ）. Expression of PPARα mRNA （A） in LPS 2h and LPS 4h groups were significantly lower than those in control group （ all P 〈 0.01 ） and PPARα （A） in LPS 4h and LPS 8h groups were significantly lower than those in control group （ all P 〈 0. 05 ）. CONCLUSION ： Our data suggest that expression of PPARα decreases in lungs of ALI rats＇ and PPARα may play a major role in acute lung injury.