长时程热性惊厥大鼠海马白细胞介素-1β表达及神经元凋亡分析

Expression of interleukin-1β and apoptosis in hippocampus of rat with prolonged febrile seizures

目的研究长时程热性惊厥（PFS）大鼠海马IL-1β表达及神经细胞凋亡情况，为探讨PFS脑损伤机制及寻求有效的防治措施提供理论依据。方法将96只14日龄SD大鼠按随机数字法分为3组：正常对照组（NC组）、高热对照组（HC组）及PFS组。采用脂多糖联合低剂量海人藻酸腹腔注射诱导建立PFS模型。HE染色观察大鼠海马神经元显微结构的改变，免疫组织化学法检测IL-1β在海马CA1区神经元细胞中的表达，原位末端标记法检测海马神经细胞凋亡情况，并分析二者之间的关系。结果1.PFS组32只大鼠均出现惊厥，惊厥发作时肛温（39．3±0．4）℃，其他2组大鼠未出现惊厥。2．PFS组在惊厥6h时间点海马CAl区TUNEL阳性细胞数高于NC组和HC组，差异有统计学意义（P均〈0．01），24h达高峰。3．免疫组织化学检测显示PFS组大鼠在惊厥发作后6h时间点以后海马IL-1β表达增强，明显高于NC组和HC组（P均〈0．01）；且海马神经元细胞凋亡程度与IL-1β的表达呈正相关（r=0．789，P〈0．01）。结论PFS后大鼠海马IL-1β表达明显增加，且与神经细胞的凋亡相关。

Objective To investigate the expression of interleukin-1β（IL-1β） and apoptosis in the hippocampus of rats with prolonged febrile seizures（PFS） ,and to provide the theoretical basis for exploring the brain damage of PFS and the effective prevention and control measures. Methods Ninety-six 14-day-old Sprague-Dawley rats were ran- domly divided into 3 groups ： normal control group （ NC group, n = 32）, hyperthermia group （ HC group, n = 32） and PFS group（n = 32）. Lipopolysaccharide combined low-dose Kainic acid of intraperitoneal injection were used to induce PFS. Then the histopathologic changes in hippocampus were viewed by HE staining and electronmicroscope,the expres- sion of IL-1β protein in hippocampus of rats was detected with immunohistochemistry methods, the neuron apoptosis was observed by TdT-mediated dUTP nick end labeling, and the relationship of both was researched. Results 1. Thirty-two rats all appeared seizures in PFS group, the average rectal temperature was （ 39.3 ±0. 4 ） ℃ ; while the rats in other groups were not convulsions. 2. The TUNEL positive cells in hippocampus CA1 of PFS group were more than that of NC group and HC group at 6 h after the PFS（ all P 〈0.01 ） ,reached its highest level at 24 h. 3. Measured by immunohisto- chemistry,the level of IL-1β in the hippocampus of PFS group was significantly higher than that of the NC group and HC group at 6 h after the PFS（ all P 〈 0.01 ）. There was a positive correlation between the expression of IL-1β and the apoptotic index in hippocampus （r = 0. 789, P 〈0.01 ）. Conclusions IL-1β expression in the hippocampus increases following PFS in rats,and the increased IL-1 β expression was correlated with neurocyte apoptosis.