惊厥持续状态后大鼠海马TLR4、IL-1β的表达及意义

摘要

Objective To observe the changes of neuron pathology and the expression of TLR4 and IL- 1βin hippocam-pus of rats after status convulsion. Methods Eighty eight male Sprague- Dawley (SD) rats were randomly divided into control group (A) and convulsion group (B). The status convulsion was induced by injection of lithium chloride- pilocarpine in group B, then the animals were sacrificed at 4h, 24h, 48h, 72h after convulsion discontinued (subgroup B1- B4). The histopathological changes in hippocampus were observed by HE staining and electron microscopy, the expression of TLR4 and IL- 1β mRNA in hippocampus were detected by RT- PCR. Results Neuronal injury was observed in group B by HE staining and electron mi-croscopy, and the changes were increased gradual y at 72h after convulsion, Compared with controls the expression of TLR4 mRNA in rat hippocampus of group B started to increase at 4h (P<0.05) and reached the peak at 72h after convulsion;while the expression of IL- 1βmRNA reached the peak at 4h (P<0.01), then gradual y decreased and returned to normal at 72h after con-vulsion P>0.05). Conclusion The expression of TLR4 and IL- 1β may be associated with brain injury in SC rats, and the early increased IL- 1βexpression may promote the expression of TLR4.%目的：观察大鼠惊厥持续状态（status convulsion，SC）后海马的病理改变及TLR4、IL-1β的动态表达,阐明免疫反应在惊厥性脑损伤发病机制中的作用。方法88只SD大鼠分为生理盐水组（A组）、SC组（B组），B组用氯化锂-匹罗卡品法成功制作SC模型后，再分为B1- B4组（分别于惊厥后4、24、48和72h处死）。光镜观察大脑皮层及海马各区形态学改变，电镜确认海马CA1区神经元超微结构变化，RT- PCR检测海马TLR4、IL-1βmRNA的动态表达。结果长程惊厥发作后，大鼠海马神经元的损伤存在动态变化，随着观察时间的延长，72h内病变逐渐加重。TLR4 mRNA于惊厥后4h开始升高（P＜0.05），并随时间延长逐步增高，于72h时达到高峰点（P＜0.01），而IL-1βmRNA在惊厥后4h即达高峰（P＜0.01），此后随时间延长而下降，至72h时已降至正常水平（P＜0.05）。结论 TLR4和IL-1β参与了惊厥性脑损伤的发生、发展过程，且IL-1β的早期升高可能对TLR4的生成有间接促进作用。