匹罗卡品诱导颞叶癫癎大鼠海马CA1区代谢型谷氨酸受体1、4、7的表达变化

Expression of metabotropic glutamate receptor 1,4,7 in CA1 region of hippocampus in rats with pilocarpine-induced temporal lobe epilepsy

目的观察匹罗卡品诱导的颞叶癫癎大鼠海马CA1区代谢型谷氨酸受体(mGluR)1、4、7的表达变化。方法 56只SD大鼠随机分为对照组、癫癎状态(SE)2 h组、SE 12 h组、SE 24 h组、SE 72 h组、SE 7 d组和SE 14 d组,每组8只。SE各组腹腔注射325 mg/kg匹罗卡品建立癫癎模型,对照组注射等量生理盐水。采用RT-PCR和免疫组织化学方法检测各组大鼠海马CA1区mGluR1、4、7 mRNA和mGluR1蛋白的表达。结果 RT-PCR检测显示,SE 24 h组mGluR1 mRNA表达较对照组显著降低,而SE 7d组则显著增加(P<0.05);SE各组mGluR4 mRNA表达与对照组差异无统计学意义(P>0.05);SE 12 h组、SE 24 h组、SE72 h组和SE 14 d组mGluR7 mRNA表达较对照组显著降低(P<0.05)。免疫组织化学检测显示,mGluR1蛋白主要存在于细胞膜上,其表达变化规律与mGluR1 mRNA一致。结论 mGluR1、4、7可能参与难治性癫癎的发病过程。

Objective To observe the expression of metabotropic glutamate receptor （mGluR） 1, 4, 7 in CA1 region of hippocampus in rats with pilocarpine-induced temporal lobe epilepsy. Methods Fifty-six SD rats were randomly divided into control group, status epilepticus （SE） 2 h group, SE 12 h group, SE 24 h group, SE 72 h group, SE 7 d group and SE 14 d group, with 8 rats in each group. Temporal lobe epilepsy models were established in SE 2 h group, SE 12 h group, SE 24 h group, SE 72 h group, SE 7 d group and SE 14 d group by intraperitoneal injection of 325 mg/kg pilocarpine, and rats in control group were injected with same amount of normal saline. RT-PCR and immunohistochemistry were employed to detect the expression of mGluRl, 4, 7 mRNA and mGluRl protein in CA1 region of hippocampus in each group. Results It was revealed by RT-PCR that the expression of mGluRl mRNA was significantly lower in SE 24 h group than that in control group, while the expression of mGluRl mRNA was significantly higher in SE 7 d group than that in control group （P〈0.05）. There was no significant difference in the expression of mGluR4 mRNA among groups （P 〉 0. 05）. The expression of mGluR7 mRNA in SE 12 h group, SE 24 h group, SE 72 h group and SE 14 d group was significantly lower than that in control group （P 〈0.05）. Immunohistochemical examination demonstrated that mGluRl protein mainly existed on cell membrane, and the changes of expression of mGluRl protein were in line with those of mGluRl mRNA. Conclusion mGluR 1, 4, 7 may be involved in the pathogenesis of intractable temporal lobe epilepsy.