红藻氨酸致痫大鼠海马区神经元凋亡的动态变化

Dynamic change of neuronal apoptosis of hippocampus in rats following kainic acid-induced seizures

目的探讨红藻氨酸(kainicacid,KA)诱导的大鼠癫痫状态海马神经元的形态学变化、凋亡情况及抗痫药物的神经保护作用。方法90只Wistar大鼠随机分为对照组、KA组和卡马西平(CBZ)组,后两组再按癫痫发作后1h、4h、12h、24h、48h和72h不同时点分为6个亚组。KA注射后,观察大鼠癫痫发作后的行为学变化;采用HE染色法观察大鼠癫痫状态海马CA1、CA3区神经元形态学改变;采用原位细胞凋亡检测法观察癫痫状态海马CA1、CA3区神经元凋亡情况。结果KA注射后,大鼠出现严重的惊厥;在癫痫发作后12h,海马CA1区、CA3区开始出现凋亡细胞[CA1区:KA组(6.53±1.36)个,CBZ组(5.85±1.68)个;CA3区:KA组(9.58±1.63)个,CBZ组(7.36±1.27)个],48h凋亡细胞达到峰值(P<0.01)[CA1区:KA组(42.263±3.28)个,CBZ组(35.39±2.36)个;CA3区:KA组(57.64±12.76)个,CBZ组(38.37±13.65)个]。经CBZ干预后凋亡细胞明显减少(P<0.05)。结论癫痫发作后的迟发性神经元死亡很可能是由凋亡引起的,CBZ可抑制癫痫状态海马神经元凋亡。

Objective To investigate the change of neuronal morphology and apoptosis in hippocampus by kainic acid（KA） induced status epilepsy（SE） in rats, and the neuroprotective effect of anti-epilepsy drug. Methods 90 Wistar rats were classified as control group, KA group and carbamazepine （CBZ） group. The posterior two groups were also divided into 6 sub-groups （ 1 h, 4 h, 12 h, 24 h, 48 h and 72 h） according to seizure attack at the different time point. To observe the change of ethology after seizure attack, the change of neuronal morphology of CA1 and CA3 sectors within the hippocampus with the Hematoxylin and Eosin（HE） stain and the neuronal apoptosis with in situ terminal deoxynucleotidyl transferase dUTP nick-end labeling （TUNEL stain ）. Results The rats appeared severe seizures after injecting KA, there were sporadic positive cells （ CA1 sector KA group 6.53 ± 1.36, CBZ group 5.85 ± 1,68. CA3 sector： KA group 9.58 ± 1.63, CBZ group 7.36 ± 1.27） in CA1 and CA3 sectors within the hippocampus at 12 h after seizure attack, the numbers of positive cells of CA1 and CA3 sectors significantly increased at 48 h post- KA treatment （ P〈 0.01 ） （CA1 sector：KA group 42. 263 ± 3.28 ,CBZ group 35.39 ± 2.36. CA3 sector： KA group 57.64 ± 12.76, and CBZ group 38.37 ± 13.65 ）. The numbers of positive cells obviously decreased by intervention with CBZ （ P 〈 0.05）. Conclusion The delayed neuronal death after KA induced SE was possibly caused by apoptosis, and CBZ can inhibit neuronal apoptosis of hippocampus at SE.