胆红素对大鼠急性肺损伤形成过程中氧自由基以及caspase-3表达的影响

目的： 探讨胆红素对抗急性肺损伤（ALI）形成的可能机制。方法: 健康雌性Wistar大鼠(190-210 g) 30只，随机分为生理盐水对照组、脂多糖（LPS）致ALI模型组、胆红素干预组。检测肺组织匀浆中羟自由基（OH^-）、过氧化氢(H₂O₂)和超氧阴离子自由基（O₂^·）含量以及肺组织中caspase-3表达的变化。结果: ①ALI模型组肺组织匀浆OH^-、H₂O₂、O₂^·含量及肺组织中caspase-3表达显著高于生理盐水对照组（均P<0.05）。②胆红素干预组肺组织匀浆OH^-、H₂O₂、O₂^·及肺组织中caspase-3表达明显高于ALI正常大鼠（均P<0.05），但少于ALI模型组（均P<0.05）。结论: ①胆红素能在一定程度上减少肺内凋亡细胞数量。②胆红素能减少ALI大鼠肺组织OH^-、H₂O₂、O₂^·水平。③ Caspase-3表达的变化有促脂多糖性肺损伤细胞凋亡作用。

Effects of bilirubin on oxygen free radicals and caspase-3 in acute lung injury rats

AIM:To investigate the mechanisms by which bilirubin inhibits acute lung injury (ALI). METHODS:30 female Wistar rats were divided into normal group, ALI group and bilirubin treatment group. ALI was induced by intravenous injection of LPS. The contents of OH^-, H₂O₂ and O₂^· in the lung as well as the expression of caspase-3 in the lungs were investigated. RESULTS:(1) The contents of OH^-, H₂O₂ and O₂^· in the lung homogenate and the expression of caspase-3 in the lungs in ALI group increased compared with those in normal group (P<0.05). (2) The contents of OH^-, H₂O₂ and O₂^· in the lung homogenate and the expression of caspase-3 in the lungs in bilirubin treatment group increased compared with those in normal group, but decreased compared with those in ALI models (P<0.05). CONCLUSION:(1) Bilirubin was shown to be able to ameliorate apoptosis in ALI rats. (2) The increase in the contents of OH^-, H₂O₂, O₂^· in ALI group indicated the development of oxidative lung injury, which was ameliorated by bilirubin. (3) Expression of caspase-3 confirmed that the model made by LPS was associated with apoptosis, which was reduced by bilirubin.