肝细胞生长因子在急性肺损伤中的作用机制

目的观察急性肺损伤（ALI）时肝细胞生长因子（HGF）的表达，探讨其作用机制。方法Wistar雄性大鼠45只，随机分为3组，模型组及干预组采用气管内注射内毒素诱导急性肺损伤，对照组在相同条件下给予等量生理盐水。注射内毒素后2、12、36h干预组自腹腔给予抗HGF抗体，其余各组在相同条件下给予生理盐水。各组动物在注射内毒素后4、14、38h后分别处死5只，取肺组织观察其病理变化，测湿／干重比及羟脯氨酸（MPO）浓度，用RT—PCR法和免疫组化法检测大鼠肺组织中HGF mRNA及蛋白的表达情况，用免疫组化法检测肺组织中增殖细胞核抗原（PCNA）的表达情况。结果模型组显示明显的肺损伤病理变化，干预组肺损伤进一步加剧；模型组肺组织湿／干重比、MPO浓度、HGF mRNA及蛋白的表达增加，干预组的湿／干重比、MPO浓度表达较模型组进一步增加，但HGF的表达则较模型组减少；干预组肺组织中PCNA表达较模型组明显下降。结论急性肺损伤时HGF表达增加，HGF通过促进上皮细胞有丝分裂来促进肺损伤的修复。

Role of Hepatocyte Growth Factor in Acute Lung Injiury of Rats

Objective To explore the expression of hepatocyte growth factor(HGF) in the acute lung injury and the mechanism of HGF treating acute lung injury.Methods Sixty Wistar rats were divided into three groups.In the model groups and anti-HGF groups,acute lung injury was induced by intratracheal instillation of endotoxin.Five rats in each group were sacrificed 2,12,36 h after intraperitoneal injection of the neutralizing HGF rabbit anti-rat IgG.In the control group,normal saline was given both intratracheally and intraperitoneally.Histological changes of the lungs were evaluated by HE stain and Masson's trichrome stain.Collagen content of the lung tissue was assessed by hydroxyproline concentration.The expression of HGF mRNA was detected by PT-PCR,and the level of HGF protein and PCNA was measured by immunohistochemistry.Results In the model groups there were obviously histological changes of the lungs,and administration of the anti-HGF IgG aggravated the lung injury.The expression of HGF mRNA and protein in model groups was significantly increased as compared with control groups,but reduced in anti-HGF groups.Anti-HGF reduced the number of PCNA-positive alveolar epithelial cells.Conclusion HGF can repair the injured lung tissue by stimulating proliferation of the epithelial cells.