惊厥持续状态中大鼠脑内神经元死亡的年龄特征  

The age-dependent features of brain selective neuron death during status convulsivus

作　　者：蒋莉[1] 蔡方成[1] 李欣[1] 张晓萍[1] 

机构地区：[1]重庆医科大学儿童医院神经内科,400014

出　　处：《中华儿科杂志》2002年第9期545-549,共5页Chinese Journal of Pediatrics

摘　　要：目的　探讨惊厥持续状态中大鼠脑内神经元死亡的年龄特征及其发生发展规律。方法分别于持续惊厥 (成年鼠 15～ 2 0min、幼鼠 2 1～ 75min)发作后 4、12、2 4、4 8、72h和 7d处死动物。光、电镜观察神经元病变 ;TUNEAL法和流式细胞仪 (FCM)检测定量研究细胞凋亡的发生率。结果　 (1)惊厥后 4h内即有明显神经元死亡。成年鼠坏死细胞数于惊厥后 2 4～ 4 8h达高峰 [(180± 38)个 ],是幼鼠 [(90 0± 5 9)个 ]的 2倍。 (2 )幼鼠除发作早期TUNEAL阳性细胞增多外 ,2 4h后即与发作前无差异。成年鼠则于 2 4～ 72h达高峰 ,较发作前高 5～ 6倍 ,较幼鼠高 3～ 4倍。 (3)FCM检测凋亡细胞发生率 :成年鼠 2 4～ 72h达高峰 [(2 8± 3 3) % ],为幼鼠 [(4 0± 3 8) % ]的 4～ 7倍。结论　 (1)长时程惊厥发作通过细胞坏死和细胞凋亡两种形式引起海马区选择性神经元死亡 ,这是一个动态过程。 (2 )神经元死亡的严重程度、主要死亡形式均有明显年龄差异。成年鼠惊厥后早期以细胞坏死为主 ,但从12h起 ,凋亡过程逐渐占优势。幼龄鼠死亡神经元数始终明显低于成年鼠 ;惊厥后早期凋亡过程已明显回落。表明幼龄鼠脑内存在神经元保护机制 ,遏制了神经元的坏死 。Objective Prolonged seizure or status convulsivus could induce brain damage, the feature of such damage is selective neuron death which occurs predominately at some regions of hippocampus. However, both clinical and our previous pathological studies could not demonstrate that the premature brain has a special resistance to brain damage from seizure. Necrosis and apoptosis are the two patters of cell death. The aim of this study was to explore the difference of the patterns of selective neuron injury after prolonged seizures or status convulsivus (SC) and explore the age dependent features of selective neuron injury in premature and mature brain. Methods Thirty adult rats (ARs) experienced 15-20 min seizures, and 30 infant rats (IRs) experienced 21-75 min seizures were sacrificed at 6 time points (4 h, 12 h, 24 h, 48 h, 72 h, 168 h) after seizure stopped. The necrotic and apoptotic neurons were observed microscopically, and comparatively studied by flow cytometry (FCM), TUNEAL and electron microscopy. The incidence of apoptotic and necrotic neurons were counted at the slices stained with TUNEAL or HE in the area of hippocampus CA 3, dentate gyrus and temporal cortex. Normal rats and rats without seizure after megimide injection were used as controls respectively. Results (1) The process of neurons′ death was shown even at 4 h after severe seizures. The peak of necrosis process reached at 24-48 h after seizure in ARs [(180±38) cells] , it was 2 times higher than IRs [ (90 0±5.9) cells] , and 4.5 times higher than control [ (38±6 )cells] . (2) In ARs, apoptotic neurons had been shown from the early stage after seizure. On TUNEAL study, a peak level of the process of apoptosis was reached at 24-72 hours which was 5-6 times higher than control and 3-4 times higher than IRs. By FCM study, there was very similar process of neuron apoptosis as the result of TUNEAL study. The peak level of apoptosis [ (28±3.3)%] was reached at 24-72 hours after prolonged seizure, which was 5-8 times higher than c

关 键 词：惊厥持续状态 年龄特征 癫痫持续状态 脑死亡 脱噬作用 动物实验 儿童 

分 类 号：R720.597[医药卫生—急诊医学]