p38丝裂原活化蛋白激酶选择性抑制剂对难治性癫痫模型大鼠神经细胞的保护作用及其机制研究

目的:研究p38丝裂原活化蛋白激酶(p38MAPK)选择性抑制剂SB202190对难治性癫痫模型大鼠神经细胞的保护作用及其机制。方法:取大鼠随机分为空白对照组、模型组、阳性对照组(卡马西平5 mg.kg-1)和SB202190低、中、高剂量组(7.5、15、30mg.kg-1),每组10只,除空白对照组外,其余各组腹腔注射海仁酸(KA)10 mg.kg-1建立难治性癫痫模型,阳性对照组和SB202190各剂量组建模前30 min腹腔注射相应药物。建模给药后按Racine分级标准对各组大鼠进行行为学评价,观察建模给药后1 h内各组大鼠的脑电图(EEG)变化,采用免疫组化法和蛋白免疫印迹法检测建模给药后3 h各组大鼠脑组织中p38MAPK蛋白的表达。结果:空白对照组无癫痫发作,EEG无明显节律性;模型组癫痫大发作,发作程度为5级,EEG出现癫痫样放电,与空白对照组比较,模型组p38MAPK阳性细胞数明显增加,其表达明显增强(P<0.01);与模型组比较,阳性对照组和SB202190 3个剂量组发作程度、EEG癫痫样放电、p38MAPK阳性细胞数及其蛋白表达均明显降低(P<0.05或P<0.01)。结论:SB202190对KA诱导的难治性癫痫模型大鼠神经细胞具有保护作用,可能与其抑制p38MAPK蛋白的表达有关。

Protective Effects of p38MAPK Selective Inhibitor on Neurone in Rats with Intractable Epilepsy and Its Mechanism

OBJECTIVE： To explore the protective effects of p38 mitogen-activated protein kinase（MAPK） selective inhibitor SB202190 on neurone in rats with intractable epilepsy and its mechanism.METHODS： SD rats were randomly divided into blank control group,model group,positive control group（carbamazepine 5 mg·kg-1） and SB202190 low-dose,medium-dose and high-dose（7.5,15,30 mg·kg-1） groups with 10 rats in each group.All of them were given kainic acid 10 mg·kg-1 i.p.to establish intractable epilepsy model,except for blank control group.Positive control group and SB202190 groups were given relevant drugs i.p.30 min before modeling.Ethology evaluation was conducted according to Racine criteria after modeling and medication.Electrocorticogram（EEG） of rats was recorded within 1 h after modeling and medication.Expression of p38MAPK protein was detected by immunohistochemistry and Western blot 3 h after modeling and medication.RESULTS： No epileptic attack was observed in blank control group,and EEG didn＇t showed obvious rhythmicity.Grand mal idiopathic epilepsy was found in model group and the degree of attack was 5;EEG showed epileptiform discharges;compared with blank control group,p38MAPK positive cell count increased significantly in model group,the expression of p38MAPK enhanced significantly（P0.01）.Compared with model group,the degree of attack,EEG epileptiform discharges,p38MAPK positive cell count and protein expression decreased significantly（P0.05 or P0.01）.CONCLUSION： SB202190 has protective effect on KA-induced intractable epilepsy rats.The mechanism may be associated with depression of p38MAPK expressions.