【摘要】 目的:研究急性一氧化碳(CO)中毒迟发性脑病(DEACMP)模型大鼠海马神经细胞凋亡及细胞外信号调节蛋白激酶1/2(Erk1/2)、Bcl-2/Bcl-xl相关凋亡蛋白(Bad)的表达,探讨DEACMP可能的发病机制.方法:体质量240～280g雄性SD大鼠48只,随机均衡分为对照组、染毒后1,3,7,14,21d组.分次腹腔注射CO纯品气体制备DEACMP模型,观察大鼠染毒后表现,并动态监测大鼠尾血碳氧血红蛋白(COHB)浓度.取各组大鼠海马组织制备石蜡病理切片,分别采用苏木精-伊红(HE)染色、末端脱氧核苷酸转移酶介导的脱氧尿苷酸缺口末端标记(TUNEL)法、免疫组织化学法观察海马神经元形态学变化、凋亡细胞数量,及Erk1/2,Bad蛋白的表达.结果:染毒后大鼠昏迷时间较长,COHB长时间(>16h)维持在高水平(>50%);染毒后7～14d海马神经细胞出现明显变性坏死;凋亡细胞数在第7～14d达到高峰(P<0.05);Erk1/2于染毒后1～21d表达水平随时间延长逐渐减低(P<0.05);Bad表达于染毒后1d升高,3d达峰值后逐渐降低,但至21d时表达仍高于正常对照组(P<0.05).结论:CO中毒后Erk1/2表达下调、Bad早期表达上调后又回落,提示Erk1/2、Bad蛋白介导了海马区神经元的凋亡,参与了DEACMP的发生.更多还原

【Abstract】 AIM:To investigate hippocampal neuronal apoptosis in model rats and expression of extra cellular signal regulated protein kinase 1/2(Erk1/2) and Bcl-2/Bcl-xl-associated death promoter(Bad) protein,and to study the possible pathogenesis of delayed encephalopathy after acute carbon monoxide poisoning(DEACMP).METHODS:Male 48 SD rats(240-280 g),were randomly divided into the control group and the carbon monoxide(CO)-poisoned group(1,3,7,14,21 d after poisoning).The latter were injected in abdominal cavity with CO in several times to establish DEACMP model.The symptoms of rats after poisoning were observed and the concentration of carboxyhemoglobin(COHB) in rats’ caudal vein were monitored dynamically.The hippocampal tissues of each group were taken to prepare paraffin pathological section and hematoxylin-eosin(HE) staining,TdT-mediated dUTP nick end labeling(TUNEL),immunohistochemical method were used to observe morphological changes in the hippocampal area,the amount of apoptotic cells and expression of Erk1/2 and Bad protein.RESULTS:CO-poisoned rats were in the coma state for a long time,and COHB were kept at higher level(>50%) for longer time(>16 h);apparent hippocampal neuronal degeneration and necrosis occurred on the 7th-14th day after poisoning;the amount of apoptotic cells also reached the highest level on the 7th-14th day(P<0.05);the expression level of Erk1/2 protein decreased gradually during 1st-21st day(P<0.05);and the expression of Bad protein increased on the 1st day and peaked on the 3rd day,then decreased,and still kept higher level than that of the control group even at the 21st day(P<0.05).CONCLUSION:The expression level of Erk1/2 decreased and that of Bad increased with a following decline after CO poisoning,which indicates that Erk1/2 and Bad protein attribute to hippocampal neural apoptosis and are involved in the pathogenesis of DEACMP.更多还原