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背景:临床上有3%～30%的急性一氧化碳中毒患者会发生一氧化碳中毒后迟发性脑病,出现以痴呆、精神症状和锥体外系症状为主的神经系统症状。目前,其发病机制还不清楚。目的:探讨一氧化碳中毒迟发性脑损伤的病理损伤机制,及高压氧对迟发性脑损伤的影响。设计:随机对照动物实验。单位:解放军第四军医大学航空航天医学系航空卫生教研室。材料:实验于2004-03在解放军第四军医大学航空航天医学系航空病理学和分子生物学实验室进行。取清洁级健康雄性Sprague-Dawley大鼠80只,单纯随机分为3组,正常对照组10只,模型组35只,高压氧组35只,后2组又分为染毒后6h、1,3,5,7,14,21d7个时间点,每个时间点5只。方法:①模型组:将大鼠放入染毒罐中熏吸入一氧化碳与空气的混合气体60min,一氧化碳的体积分数保持在2500×10-6,制备急性CO中毒动物模型。②高压氧组:同模型组造模,染毒后3h开始行高压氧治疗,压力0.2MPa,氧的体积分数保持在0.90以上熏整个过程共115min,染毒后前3d2次/d,之后1次/d,每周休息1d。③正常对照组不干预。主要观察指标:①采用组织病理学、免疫组织化学等方法检测大鼠染毒后各时间点大鼠脑组织病理改变的特点。②通过细胞超微结构观察和原位末端转移酶标记(TUNEL)等方法进行细胞凋亡的检测,观察急性各组大鼠脑神经元凋亡的发生情况。结果:造模后大鼠死亡率约为10%。①模型组大鼠脑内发生广泛的病理损伤,脑皮质、海马、纹状体和小脑等部位神经元出现变性坏死,其中大脑皮质、海马等部位损伤较重。苏木精-伊红、TUNEL染色和电镜观察表明大鼠海马神经元发生凋亡,凋亡神经元从染毒后第3天开始显著增加,第7天达到高峰穴P<0.01雪,以后逐渐减少。②高压氧组:与模型组相比,脑内神经元变性坏死明显减轻,各时间点大鼠海马区损伤均轻于模型组;凋亡神经元数目减少,尤以中毒后5和7d明显(P<0.01)。高压氧促进模型大鼠海马区Bcl-2蛋白表达熏尤以CO暴露后3,5d明显(P<0.01)。结论:①急性一氧化碳中毒大鼠出现广泛的迟发性神经元损伤,表现为迟发的神经元坏死和凋亡。②高压氧治疗可以有效减少变性坏死神经元熏促进凋亡抑制基因bcl-2表达熏从而抑制神经元坏死和凋亡。
Background: In clinical practice, 3% to 30% of patients with acute carbon monoxide poisoning may develop delayed encephalopathy after carbon monoxide poisoning. Neurological symptoms such as dementia, psychotic symptoms and extrapyramidal symptoms occur. At present, its pathogenesis is unclear. Objective: To investigate the pathological damage mechanism of delayed brain injury caused by carbon monoxide poisoning and the effect of hyperbaric oxygen on delayed brain injury. Design: Randomized controlled animal experiments. Unit: Department of Aeronautics and Astronautics, Fourth Military Medical University. MATERIALS: Experiments were performed at the Laboratory of Aeropathology and Molecular Biology, Department of Aeronautics and Astronautics, Fourth Military Medical University of PLA, 2004-03. Eighty healthy male Sprague-Dawley rats were randomly divided into three groups randomly: normal control group (n = 35), model group (n = 35) and hyperbaric oxygen group (n = 35) 3,5,7,14,21 d7 time points, each time point 5 only. Methods: ①Model group: The rats were exposed to the canister for smoking for 60 minutes and the volume fraction of carbon monoxide was kept at 2500 × 10-6. The animal model of acute CO poisoning was prepared. ② hyperbaric oxygen group: the same model group modeling, 3h after exposure to hyperbaric oxygen therapy, pressure 0.2MPa, the oxygen volume fraction remained above 0.90 smoked the entire process a total of 115min, 3d3 times before / d, then 1 Times / d, 1d weekly break. ③ normal control group did not interfere. MAIN OUTCOME MEASURES: ① The histopathology, immunohistochemistry and other methods were used to detect the pathological changes of rat brain tissue at different time points after exposure. ② Apoptosis was detected by ultrastructural observation and TUNEL, and the apoptosis of neurons in the acute groups were observed. Results: The mortality of rats after modeling was about 10%. ① In the model group, extensive pathological damage occurred in the brain. Neurons in the cerebral cortex, hippocampus, striatum and cerebellum were denatured and necrotic. The cortex and hippocampus were damaged seriously. Hematoxylin and eosin, TUNEL staining and electron microscopy showed that apoptosis of hippocampal neurons occurred in rats. The number of apoptotic neurons increased significantly from the third day after exposure, reaching peak point P <0.01 on the seventh day, cut back. ② hyperbaric oxygen group: Compared with the model group, the degeneration and necrosis of neurons in the brain were significantly reduced. The hippocampal lesion in rats at each time point was lighter than the model group. The number of apoptotic neurons decreased, especially at 5 and 7 days after poisoning P <0.01). The expression of Bcl-2 protein in hippocampus of hyperbaric oxygen-induced rats was significantly higher than that on the 3rd and 5th day after CO exposure (P <0.01). Conclusion: ①Acute carbon monoxide poisoning in rats with extensive delayed neuronal damage, manifested as delayed neuronal necrosis and apoptosis. ② hyperbaric oxygen therapy can effectively reduce the degeneration of necrotic neurons smoked promote apoptosis inhibitor bcl-2 expression smoked to inhibit neuronal necrosis and apoptosis.