血管紧张素转化酶2在内毒素诱导大鼠急性肺损伤中的作用

目的探讨血管紧张素转化酶2（ACE2）在内毒素（LPS）诱导大鼠急性肺损伤（ALI）中的治疗作用。方法 24只Wistar大鼠随机分为三组：对照组、ALI组和ACE2治疗组（ACE2组）。LPS静脉注射法复制大鼠ALI建立模型。ACE2组在接受LPS静脉注射后立即给予腹腔注射重组大鼠ACE2 0.1 mg/kg。于术后2 h取大鼠动脉血,全自动动脉血气分析仪测定动脉血气;测肺组织湿重/干重（W/D）比值;酶联免疫吸附试验法（ELISA）测定各组大鼠肺组织中TNF-α、IL-8和IL-1β含量;光学显微镜观察肺组织病理形态学改变。结果成功复制了大鼠LPS肺损伤模型。ACE2干预后可以明显改善ALI大鼠动脉血氧和水平（P〈0.05）、降低W/D比值（P〈0.05）、降低肺组织匀浆内TNF-α、IL-8和IL-1β质量浓度;改善ALI大鼠肺组织损伤及病理评分。结论 ACE2对大鼠LPS诱导肺损伤有治疗作用。

Therapeutic Effect of Angiotensin-converting Enzyme 2 on Lipopolysaccharide-induced Acute Lung Injury in Rats

Objective To explore the therapeutic effect of angiotensin-converting enzyme 2（ ACE2） on lipopolysaccharide（ LPS）-induced acute lung injury（ ALI） in a rat model. Methods Twentyfour Wistar rats were randomly divided into a control group,an ALI group,and an ACE2 group. The rat ALI model was established by intravenous injection of LPS. Then the rats in the ACE2 group received intraperitoneally injection of recombinant rat ACE2 by 0. 1 mg /kg immediately after LPS injection. All rats were sacrificed 2 hours later. Rat arterial blood gas was analyzed and wet /dry（ W /D） weight ratio of lung tissue was measured. Concentrations of TNF-α,IL-8 and IL-1β in lung tissue homogenates were measured by ELISA. Pulmonary pathological changes were evaluated by hematoxylin-eosin stain under light microscope.Results ALI induced by LPS was successfully established in the rats. ACE2 pretreatment markedly impoved PaO2 level of the ALI rats（ P 〈 0. 05）,and decreased the lung W /D ratio（ P 〈 0. 05）. The concentration of TNF-α,IL-8 and IL-1β in lung tissue homogenates were also inhibited by ACE2. And the lung histopathological changes and score were attenuated in the ACE2 group. Conclusion ACE2 treatment has therapeutic effects on ALI induced by LPS.