急性CO中毒大鼠脑内VCAM-1表达CD4+T淋巴细胞浸润规律的研究及高压氧干预后的变化

目的 观察急性CO中毒后大鼠脑内血管内皮细胞黏附分子-1（VCAM-1）表达、CD4^＋T淋巴细胞浸润情况，从系统细胞免疫反应角度探讨迟发性脑病（DNS）与免疫反应的关系。方法 30只SD雄性大鼠随机分为对照组，染毒后1、3、7d组和高压氧（HBO）治疗7d组，每组6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VCAM-1表达、CD4^＋T淋巴细胞浸润情况。结果 对照组无VCAM-1表达、无CD4^＋T淋巴细胞浸润；各染毒组大鼠脑内微血管内皮细胞和变性坏死的神经元均有VCAM-1不同程度的表达。染毒后1d组为表达高峰（P〈0．01），3d组VCAM-1的表达数量有所减少。此时，局部大脑皮层开始有CD4^＋T淋巴细胞浸润；至染毒后7d，在部分变性坏死的神经元上仍有VCAM-1的持续表达，而CD4^＋T淋巴细胞浸润达高峰（P〈0．01）。染毒后立即进行HBO治疗7d，其VCAM-1、CD4^＋T淋巴细胞均显著减少，与染毒后7d组相比差异有统计学意义（P〈0．05）。结论 系统细胞免疫反应可能参与了DNS的发生。

Expression of VCAM-1 and Infiltration of CD4+ T lymphocytes in brains of acute CO-poisoning rats and development after treated by HBO

Objective To investigate the expression of Vascular Cell Adhesion Molecule-1 (VCAM-1) and the infiltration of CD4 T lymphocytes in brains of acute Carbon Monoxide (CO) poisoned rats and study the relation of Delayed Neuropathological Sequelae (DNS) and immunoreaction through systemic cell immunoreaction . Methods CO-poisoned rats model was established in Twenty-four SD male rats and another six as control. The poisoned rats were equally divided into four groups: 1, 3,7 d post-poisoning and 7 d post-Hyperbaric Oxygen(HBO) treatment respectively. HE and Immunohistochemical staining were performed on frozen sections to observe the change of pathological morphous and the expression of VCAM-1 and the infiltration of CD4 T lymphocytes in brains of each group rats as compared with that of the control rats. Rrsults Immunohistochemical staining showed that there were expressions of VCAM-1 in endothelial cells of cerebral microvessels and denaturatd neurons in poisoned group rats at a disparate degree, but no VCAM-1 expression and CD4 T lymphocytes infiltration were shown in control rats. VCAM-1 expression reached the peak at 1th d(P<0.01) and became weak at 3th d and kept at 7th d, while CD4 T lymphocytes initiated infiltration in poisoned rats partial cerebral cortex at 3th d and reached the peak at 7th d(P<0.01). Moreover, the results of VCAM-1 expression and CD4 T lymphocytes decreased greatly at HBO group and they both possessed significant statistical difference (P<0.05) respectively compared with that of 7th d post-poisoning. Conclusions Systemic cell immunoreaction was contributed to DNS possibly.