摘要
目的观察选择性一氧化氮合酶抑制剂氨基胍(AG)对大鼠内毒素性肺损伤(ALI)细胞凋亡的影响,探讨AG对肺损伤组织的保护作用及其机制。方法健康♂SD大鼠,随机分为:①对照组;②模型组(LPS组);③AG治疗组。其中LPS组和AG治疗组按治疗时间又分为给LPS3h后治疗3h(3h+3h)组和给LPS6h后治疗3h(6h+3h)组,AG治疗组分别于给LPS3h和6h后给AG(100mg·kg-1),ip给药,LPS组给等量的生理盐水;(3h+3h)组于注射LPS6h后处死大鼠;(6h+3h)组于注射LPS9h后处死大鼠,每组8只动物。模型组、AG治疗组iv注射LPS复制内毒素性肺损伤大鼠模型,对照组给等量生理盐水。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(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;光镜、电镜观察肺组织病理变化。结果与对照组比较,大鼠肺损伤后,iNOSmRNA表达增强,eNOSmRNA表达减弱,nNOSmRNA表达没有明显变化;细胞凋亡率、Caspase3和Bax蛋白表达明显升高,Bcl-2蛋白表达下降,Bcl-2/Bax降低;肺损伤3h用AG治疗3h后,iNOSmRNA表达、细胞凋亡率、Caspase-3和Bax蛋白表达低于对照组,Bcl-2蛋白表达、Bcl-2/Bax高于对照组,肺组织病理改变减轻;肺损伤6h用AG治疗3h后,治疗效果较差。结论AG在较早时候给药可减轻内毒素性肺损伤,可能与减弱iNOSmRNA和Caspase-3表达、增强Bcl-2蛋白表达、减弱Bax蛋白表达、调节Bcl-2蛋白/Bax蛋白平衡有关。
Aim To investigate the effect and the possible mechanism of aminoguanidine （AG） on the lipopolysaccharide（LPS）-induced acute lung injury in rats. Methods Male SD rats were randomly divided into 3 groups： （1） Control group; （2） LPS group; （3） AG group. AG was administrated in AG group, saline was administrated in control group and LPS group. LPS group and AG group were further divided into 2 subgroups according to the duration of ALI：3 h ＋ 3 h group and 6 h ＋3 h group. In AG group and LPS group, LPS was administrated. Saline was administrated in control group. Expressions of NOS mRNA in the lung tissue were respectively measured with RT-PCR method; Apoptosis, the expression of Caspase-3 protein, Bcl-2 and bax were respectively detected with Flow Cytometry （FCM）, Western blot analysis, and immunohistochemisty （IHC） ; the pathological changes of lung tissue were observed by light and electron microscope. Results Compared with that of the control group, the expression of iNOS mRNA was significantly increased; the eNOS mRNA was significantly decreased; apoptosis of pulmonary cells, the expression of Caspase-3 and Bax protein were significantly increased; the expression of Bcl-2 was decreased in alveolar and airway epithelial cells in LPS group respectively. Degree of ALI was gradually worsened after administration of LPS. In AG （3 h ＋ 3 h） group, the percentage of apoptotic cells, the expression of caspase-3 and Bax protein were decreased respectively, the expression of Bcl-2 and the ratio of Bcl-2/Bax were increased and the lung damage was improved respectively compared with that of the LPS（3 h ＋ 3 h） group. Conelusion Relatively early administration of AG could ameliorate LPS-induced acute lung injury in rats. The possible mechanism is that AG could reduce the expression of iNOS mRNA, Caspase-3 and Bax protein, increase the expression of Bcl-2 protein, and regulate the balance between Bcl-2 and Bax protein.
出处
《中国药理学通报》
CAS
CSCD
北大核心
2007年第1期28-32,共5页
Chinese Pharmacological Bulletin
基金
国家人事部留学人员重点资助项目(No9900789)
河北省博士基金资助项目(No995470151)
关键词
急性肺损伤
氨基胍
细胞凋亡
LPS
一氧化氮合酶
acute lung injury
aminoguanidine
apoptosis
lipopolysaccharides
nitric oxide synthase
