L-硝基精氨酸对大鼠内毒素性肺损伤治疗作用及其机制的研究  

Effect of NG-nitro-L-arginine on endotoxin-induced lung injury in rats

作　　者：李立萍[1] 张建新[1] 李兰芳[1] 

机构地区：[1]河北省医学科学院,石家庄市050021

出　　处：《河北医药》2010年第13期1672-1674,共3页Hebei Medical Journal

基　　金：国家人事部留学人员重点资助项目(编号:9900789);河北省博士基金资助项目(编号:99547015D);河北省医学科学研究重点课题(编号:20090040)

摘　　要：目的探讨L-硝基精氨酸(NG-nitro-L-arginine,L-NA)对内毒素性肺损伤大鼠肺表面活性物质(PS)和细胞凋亡的影响,探讨L-NA对肺损伤的保护作用及其机制。方法健康雄性SD大鼠采用舌下静脉注射脂多糖(LPS)复制肺损伤模型,分别于给予LPS1h和6h后给予0.9%氯化钠溶液(对照组及LPS组,静脉给药)和L-NA(20mg/kg,静脉给药)(L-NA治疗组),治疗3h,取肺组织,原位杂交法(ISH)测定肺组织肺表面活性物质蛋白A(SP-A)mRNA;流式细胞术(FCM)检测肺细胞凋亡率;Westernblot法检测Caspase-3蛋白的表达;免疫组化法测定Bcl-2和Bax蛋白的表达。结果与对照组比较,大鼠肺损伤后SP-AmRNA表达明显下降(P<0.01);细胞凋亡率、Caspase-3和Bax蛋白表达明显升高(P<0.01),Bcl-2蛋白表达和Bcl-2/Bax降低(P<0.01);肺损伤1h用L-NA治疗3h后,SP-AmRNA阳性细胞表达明显增强(P<0.05),细胞凋亡率降低(P<0.05);但Caspase-3、Bax、Bcl-2蛋白表达、Bcl-2/Bax与LPS组比较没有明显的变化(P<0.05),肺组织病理改变减轻,肺损伤6h用L-NA治疗3h对LPS引起的以上变化没有明显影响。结论肺损伤1h后给予L-NA可减轻内毒素性肺损伤,增强PS表达,减少细胞凋亡是其机制之一。Objective To investigate the effects of NG-nitro-L-arginine （L-NA）on the lipopolysaccharide （LPS） -induced pulmonary surfactant （PS） and pulmonary cells apoptosis. Methods The models of ALI were established by injection （iv） with LPS 5 mg/kg in male Sprague-Dawley （SD） rats. L-NA （20 mg/kg ip） was administrated at 1 h or 6h after LPS injection respectively for 3h. The treatment lasted for 3h, and the rats were sacrificed at 4h or 9h after LPS injection. The expressions of SP-A mRNA in the lung tissue were measured by ISH methods,and apoptosis factors, caspase-3, Bcl-2 and Bax were detected respectively by flow cytometry, Western Blot and immunohistochemisty. Results As compared with that of saline group, SP-A mRNA in lung tissue of rats was significantly decreased by LPS in LPS group （ P 〈 0.05 ）. As compared with that of saline group, the apoptosis of pulmonary cells and caspase-3 expression were significantly increased, however, Bcl-2 was decreased, while Bax was increased in alveolar and airway epithelial cells in LPS group. As compared with LPS group, the treatment with L-NA at lh after LPS injection increased markedly the expressions of SP-A mRNA and decreased pulmonary apoptotic cells, but there were no significant changes in the expression of caspase-3, Bcl-2 and Bax between L-NA group and LPS group,while L-NA given at 6h after LPS had no significant effect on the LPS-induced changes. Conclusion The relatively early administration of L-NA can protect LPS-induced lung injury by up-regulating the expression of PS and inhibiting cell apoptosis.

关 键 词：L-硝基-精氨酸 急性肺损伤 脂多糖 肺表面活性物质 细胞凋亡 

分 类 号：R563[医药卫生—呼吸系统]