宣白承气汤对急性肺损伤大鼠肺组织脂多糖结合蛋白和Toll样受体4mRNA表达的影响

摘要

OBJECTIVE To investigate the effects of Xuanbai Chengqi (XBCQ) Decoction on lipopolysaccharide-binding protein (LBP) and toll-like receptor 4 (TLR4) mRNA expressions in lipopolysaccharide (LPS) induced acute-lung-injured rat model.METHODS 32 healthy Wistar male rats were randomly divided into 4 groups: normal group, model group, dexam-ethasone group and XBCQ group. Each group had 8 rats. LPS (6 mg/kg) was injected into the model group and each treatment group to copy ALI animal model. The normal group and model group were given the same volume of physiological saline. The dosage of dexamethasone group was 5mg/kg ip. The dosage of XBCQ group was 7 560 mg/kg ig. The LBP and TLR4 mRNA expressions of lung tissue were measured by real time fluorescence quantitative per (RT-PCR). Protein expressions of TLR4 in lung tissue were measured by ismmunohistochemical method. The pathological manifestation of the lung tissue was observed. RESULTS Compared with normal group, the bronchus LBP mRNA of model group and expressions of TLR4 mRNA and staining positive cell area occupation ratio of protein were greatly increased in the model group (P＜0.05). Compared with the model group, expressions of TLR4 mRNA and protein were decreased in XBCQ group (P＜0.05). Light microscope indicated large areas of pulmonary hemorrhage and necrosis in model group. The pathological changes of XBCQ group were less than the model group. The interstitial inflammation of bronchiole was slight. CONCLUSION XBCQ Decoction can lessen the lung tissue injury of rat caused by endotoxin and has protective effects on lung injury. The mechanism is possibly related to the inhibition of the expressions of TLR4 mRNA and protein in injured lung tissues.%目的 探讨宣白承气汤对脂多糖(lipopolysaccharide,LPS)诱导的急性肺损伤(acute lung injury,ALI)大鼠肺组织脂多糖结合蛋白(lipopolysaccharide-binding protein,LBP)和Toll样受体4(toll-like receptor 4,TLR4) mRNA表达的影响.方法 健康雄性Wistar大鼠32只,随机分为正常组、模型组、地塞米松组、宣白承气汤组共4组,每组8只.模型组与各治疗组大 鼠采用尾静脉注射LPS(6 mg/kg)复制ALI模型.正常组和模型组给等容积生理盐水ig,地塞米松组给药为5 mg/kg ip,宣白承气汤组给药为7 560 mg/kg ig.采用实时荧光定量PCR法测定肺组织LBP、TLR4 mRNA表达.免疫组化ABC法测定肺组织TLR4蛋白表达.观察肺组织病理变化.结果 与正常组比较,模型组的支气管LBP mRNA、TLR4mRNA和蛋白染色阳性细胞面积率表达均升高(P＜0.05).与模型组比较,宣白承气汤组TLR4 mRNA和蛋白染色阳性细胞面积率表达均降低(P＜0.05).病理学观察,模型组大鼠肺泡腔内充满炎性渗出物和出血,宣白承气汤组大鼠肺组织病理改变轻于模型组,肺细支气管轻度间质性炎症.结论 宣白承气汤能减轻内毒素致ALI大鼠肺组织损伤,对肺损伤有保护作用,其机制可能与其降低肺组织TLR4 mRNA和蛋白表达有关.