神经生长因子对红藻氨酸致大鼠海马神经细胞半胱氨酰天冬氨酸蛋白酶-3表达的影响

Effect of Nerve Growth Factor on Expression of Caspase-3 in Hippocampus of Rats with Seizures Induced by Kainic Acid

目的观察神经生长因子(NGF)对红藻氨酸(KA)致大鼠海马半胱氨酰天冬氨酸蛋白酶-3(Caspase-3)表达的影响,探讨其对癫大鼠神经细胞的保护作用及其机制。方法将60只日龄21～30 d健康大鼠随机分为9 g.L-1盐水对照组(A组),KA致模型对照组(B组),NGF治疗组(C组),每组20只。KA用9 g.L-1盐水配成2 g.L-1,B组、C组大鼠以4 mg.kg-1腹腔注射。注射完观察记录其性发作的潜伏期和性发作的级别,并进行EEG和病理学检查。C组每只大鼠腹腔注射KA20～30 min予NGF4μg.kg-1腹腔注射。A组用9 g.L-1盐水2 mL.kg-1灌胃和腹腔注射。分别于KA注射6 h、1 d、3 d时将各组大鼠处死5只,常规方法灌注固定,制作冷冻切片。用免疫组织化学染色SP法检测大鼠海马Caspase-3表达,并用HPIAS-2000显微图像定量分析系统进行定量分析。结果B组、C组大鼠注射KA后30 min左右开始出现性发作,EEG和病理学检测均显示癫发作特征。C组大鼠注射3 d后,Caspase-3阳性神经元计数为7.10±2.80,B组为18.40±3.86;A组为0.34±0.06。C组大鼠海马Caspase-3阳性神经元计数与B组相同时间点比较均减少,差异有统计学意义(Pa<0.05);C组大鼠海马Caspase-3阳性神经细胞平均灰度值各时间点均小于B组;C组注射3 d后,灰度值为90.64±4.24,B组为210.95±6.25,二组比较差异有统计学意义(P<0.05)。结论NGF能抑制癫大鼠海马Caspase-3表达,对癫发作大鼠具有神经细胞保护作用。

Objective To observe the effect of nerve growth factor（NGF） on Caspase - 3 expression in hippocampus of epileptic rats induced by kainie acid（KA） and explore the protective effect and mechanisms of NGF on the epileptic neuroeytes. Methods Sixty healthy rats aged 21 to 30 days were randomly divided into 3 groups,each of whicb included 20 rats. Rats in group A were treated with 9 g · L^-1 sodium, rats in group B were treated with KA,rats in group C were treated with KA and NGF. Concentration of KA was 2 g · L^-1 diluted by 9 g · L^-1 sodium ; KA was injected into rats in group B and group C, intraperitoneally. Then state of seizure was recorded, and EEG and pathological section were performed. Five rats in each group were sacrificed by perfusion with paraform respectively at 6 hour, on the 1 ^st day, on the 3 ^rd day after injection of KA. Specimen was sampled and made into frozen section. Expression of Caspase - 3 in hippocampus of epileptic rats was analyzed by immunohistoehemistry. And microscope image measuring and analysis instrument was used to analyze image of expression. Results Symptoms of seizure appeared 30 rain after injection of KA. Seizure was proved by detection of EEG and pathological section. Expressions of Caspase - 3 detected by immunohistochemistry in group C decreased at every time spot were higher than those in group B, and the defferenees between 2 groups had statistically signifieant（Pa 〈0.05）. Counts of positive neurons in group C and group B was 7.10 ±2.80 and 18.40 ± 3.86, respectively,3 days after injection, and that in group A was 0.34 ± 0.06. Mean grey level value in group C and B were similar to count of positive neurons. Mean grey level value in group C and B was 90.64 ± 4.24 and 210.95 ± 6.25, respectively,3 days after injection, and difference between 2 groups had statistically signiflcant（P 〈 0. 05）. Conclusions NGF can inhibit the expression of Caspase - 3 caused by epileptic seizure in rats. NGF can protect nerve cells from epileptic seizure induced by KA in rats.