摘要目的 研究大鼠急性肺损伤时循环及肺组织血管紧张素Ⅱ(AngⅡ)含量的变化,探讨AngⅡ在急性肺损伤发病中的作用.方法 清洁级SD大鼠30只,随机分为正常对照组(n=6)和模型组(n=24),模型组又按注射脂多糖(LPS)后3、6、9、12 h四个时间点分成4组,每组6只.分别于静脉注射LPS后各分组时间点观察大鼠一般情况、血压、动脉血气分析、肺组织湿质量/干质量(W/D)比值、肺组织病理改变,放免法测定血浆及肺组织AngⅡ的含量的变化,所有观察指标采用单因素方差分析与正常对照组比较.结果 与正常对照组比较,pH值和动脉血氧分压显著降低(P＜0.05),而二氧化碳分压及肺W/D比值均显著高于对照组(P＜0.05),病理形态学积分分析显示肺组织受损(P＜0.01).ALI大鼠血浆及肺组织AngⅡ均升高(P＜0.05),其中血浆AngⅡ在9 h时点达峰值,而组织Ang Ⅱ浓度在各观察时间点持续上升.结论 ALI时肺组织和血中Ang Ⅱ大量释放,提示ALI时伴有全身及肺局部肾素-血管紧张素系统的激活.

abstractsObjective To investigate the changes in circulatory and pulmonary monary angiotensinⅡin rats with acite lung injury(ALI)and explore the role of angiotensinⅡin ALI.Method Thirty S-D rats were randomly divided into control group(n=6)and ALI group(n=24).The ALI group was further divided into four subgroups of observation at various intervals,3,6,9 and 12 hours after administration of lipopolysaccharide (LPS)into the femoral vein(each n=6).The indices rate,blood gas analysis,wet weight/dry weight(W/D)ratio of lung lobes,and pathological changes were successively observed at 3,6,9,and 12 hours after injury.The content of angiotensinⅡin lung tissue and blood plasma were detected at above set intervals by radioimmunoassay.Data of these assays were analyzed by one-factor analysis of variance.Results Compare with the control group,pH and PaO2 of arterial blood in ALI group decreased significantly(P＜0.05)at all intervals and PaCO2 of arterial blood in ALI group decreased significanfly(P＜0.05).at all intervals and PaCO2 of arterial blood and lung W/D weight ratio increased significantly(P＜0.05),and scores of lung histopathology denoted the lung injuried(P＜0.01).After injury of lung,angiotensin Ⅱ content increased markedly in lung homogenate and blood plasma (P＜0.05).Angiotensin Ⅱ content in blood plasma reached peak value at 9 hours,and content of angiotensin Ⅱ in lung homogenates kept on increasing at allintervals of observation.Conclusions A large amount of angiotensin Ⅱ releases into lung tissue and blood plasma during ALI,suggesting systemic and pulmonary rennin-angiotensin systems are activated.