CO中毒致迟发性脑病大鼠脑内CD4+T淋巴细胞浸润及神经胶质酸性蛋白的表达

目的观察CO中毒致迟发性脑病（DNS）大鼠脑内CD4^＋T淋巴细胞浸润以及神经胶质酸性蛋白（GFAP）的表达情况，探讨CO中毒致DNS的病理过程。方法25只SD雄性大鼠随机分为对照组、染毒后3、7、10、20d组，每组5只。采用HE和免疫组织化学染色方法，观察染毒后各时间点大鼠脑内病理形态学变化，及CD4^＋T淋巴细胞浸润和GFAP的表达情况。结果HE染色结果显示：各染毒组在大脑皮层及海马均出现神经细胞不同程度的变性、坏死，染毒后7d组最重。免疫组织化学染色结果显示：对照组无CD4^＋T淋巴细胞浸润，有少量GFAP表达；各染毒组不同脑区CD4^＋T淋巴细胞、GFAP均有不同程度的浸润和表达。CD4^＋T淋巴细胞染毒后3d开始浸润，7d达峰值，两者在数量上差异有统计学意义（P〈0．01）。各组染毒后GFAP均有大量表达，随染毒时间延长表达数量呈上升趋势。结论CD4^＋T淋巴细胞可能参与了CO中毒致DNS的免疫病理过程，GFAP阳性细胞对CO中毒引发的DNS可能具有保护作用。

Infiltration of CD4+ T lymphocytes and expression of GFAP in the brain of rats with CO poisoning induced delayed neuropathological sequelae

Objective To observe the infiltration of CD4+ T lymphocytes and the expression of GFAP in the brain of rats with CO poisoning induced delayed neuropathological sequelae ( DNS) , and to explore the pathological process of DNS. Methods Twenty-five Sprague-Dawley male rats were randomly divided into poisoned rat groups and the control group. Poisoned rats were divided into 3,7, 10,20 d post-poisoning groups, every group contained 5 rats. HE staining and immunohistochemistry were performed on frozen sections to observe the pathomorphology changes of brains, the infiltration of CD4+ T lymphocytes and the expression of GFAP in each group. Results HE staining revealed that neurocytes in poisoned rat cerebral cortex and cornu ammonis displayed denaturation and necrosis, especially in the 3 d group. Immunohistochemistry exhibited no infiltration of CD4+T lymphocytes and less expression of GFAP in the control group. However, different brain areas in CO poisoned rats all displayed a higher number of CD4+ T lymphocytes and much more expression of BFAP,as compared with the controls. CD4+ T lymphocytes initiated infiltration on the 3rd day and reached the peak on the 7th day. GFAP was highly expressed in all four poisoned groups, showing a time-dependent relationship. Conclusions CD4+ T lymphocytes may participate in the pathological process of DNS in CO poisoned rats and GFAP-positive cells may exert protective effects on the DNS rats following CO poisoning.