LPS性肺损伤大鼠一氧化氮合酶表达和肺细胞凋亡变化  

Changes of pulmonary apoptosis and NOS mRNA in the lipopolysaccharide-induced acute lung injury

作　　者：李立萍[1] 张建新[1] 李兰芳[2] 尚涛[2] 

机构地区：[1]河北医科大学药理学教研室,河北石家庄050017 [2]河北省医学科学院药物研究所,河北石家庄050021

出　　处：《中国病理生理杂志》2007年第10期1996-2001,共6页Chinese Journal of Pathophysiology

基　　金：国家人事部留学人员重点资助项目(No.9900789);河北省博士基金资助项目(No.995470151)

摘　　要：目的:观察内毒素性肺损伤过程中肺细胞凋亡和一氧化氮合酶(NOS)mRNA表达的时程性变化及关系,探讨LPS性肺损伤(ALI)的发病机制。方法:健康雄性SD大鼠48只,随机分成2组:①对照组:静注等量生理盐水;②模型组(LPS组):静注LPS复制ALI模型,分别于给药1、3、6、9及12h后采集样品;逆转录聚合酶链反应(RT-PCR)法测定肺组织中NOSmRNA表达变化;电镜、流式细胞术检测肺细胞凋亡率;免疫组化法测定Bcl-2和Bax;光镜、电镜观察肺组织病理变化。结果:与对照组比较,LPS组iNOSmRNA表达随时间延长而增强,给予LPS 3 h后有显著差异(P<0.05),eNOSmRNA随时间延长而降低,给LPS 3 h时有显著差异(P<0.05),nNOSmRNA在观察时间内没有变化;光镜和电镜下可见在观察时间内1 h起肺损伤随时间延长加重;流式细胞术显示LPS组凋亡细胞随时间延长增多,9 h达高峰,12 h有所降低;免疫组化结果显示,LPS组随时间延长Bcl-2减少,主要表现在肺上皮细胞,Bax增多;对照组无明显变化。结论:不同一氧化氮合酶在ALI中表达强度不同;抗凋亡蛋白Bcl-2和促凋亡蛋白Bax是ALI时调节细胞凋亡的途径之一;一氧化氮合酶可能通过调节Bcl-2和Bax平衡而影响凋亡。AIM： To observe the chronological changes of pulmonary apoptosis and the expression of iNOS mRNA, nNOS mRNA and eNOS mRNA in lipopolysaccharide （LPS） - induced acute lung injury （ALI） and to investigate the mechanisms of ALI. METHODS ： Rats were randomly divided into 2 groups ： control group and LPS treated group. The rats were injected with either saline or LPS and killed at 1, 3, 6, 9 and 12 h after LPS injection. The expressions of iNOS mRNA, nNOS mRNA and eNOS mRNA in the lung tissue were respectively measured with RT - PCR methods. Apoptosis and expressions of Bcl -2 and Bax were respectively determined by flow cytometry （FCM） and immunohistochemistry （IHC）. The pathological changes of lung tissue were observed under light and electron microscope. RESULTS： Com- pared with that in control group, the expression of iNOS mRNA was significantly increased at 3, 6, 9 and 12 h after administration of LPS （P 〈 0. 05）. The eNOS mRNA was significantly decreased at 3,6, 9 and 12 h after administration of LPS （ P 〈 0.05 ）. The nNOS mRNA had no significant change during the 12 h in LPS group. Degree of ALI was gradually worsened after administration of LPS. Apoptosis of pulmonary cells was significantly increased, and reached the top level at 9 h after administration of LPS （ P 〈 0. 01 ）. The expression of Bcl - 2 was n;arkedly decreased and the expression of Bax was significantly enhanced in alveolar and airway epithelial cells in LPS treated group. CONCLUSION： The expressions of iNOS mRNA, eNOS mRNA and nNOS mRNA are not identical in LPS - induced acute lung injury. NOS regulates the apoptosis of pulmonary cells through affecting the balance of Bcl - 2 and Bax.

关 键 词：急性肺损伤 细胞凋亡 脂多糖类 一氧化氮合酶 

分 类 号：R363[医药卫生—病理学]