母体IgG对N-甲基-D-天冬氨酸诱导乳鼠痉挛发作模型的作用及其对脑FOS蛋白的影响

目的探讨母体IgG对N-甲基-D-天冬氨酸（NMDA）诱导Wistar乳鼠痉挛发作模型抗痉挛的作用机制及其对脑内FOS蛋白的影响。方法从母鼠取血后提取γ球蛋白,采用离子交换法（DEAE-52）提纯大鼠母体IgG。将30只Wistar乳鼠随机分为3组：对照组（n=6）,NMDA组（n=12）和母体IgG组（n=12）。母体IgG组生后第11天起,于8：00时连续给予皮下注射所提取的各自母体IgG10mg·kg^-1·d^-1,所有注射剂量均稀释至5mL。对照组和NMDA组同时同部位注射等剂量生理盐水。NMDA组和母体IgG组生后第15天在分别注射生理盐水和母体IgG1h后,给予腹腔注射NMDA15mg·kg^-1·d^-1,诱发大鼠痉挛发作,制作Wishar乳鼠痉挛发作模型。对照组则在皮下注射生理盐水1h后腹腔注射生理盐水15mL·kg^-1。观察比较NMDA组和母体IgG组痉挛发作情况,采用免疫组化法观察各组乳鼠脑神经细胞FOS蛋白阳性细胞的表达数量。结果①对照组始终未出现临床症状。NMDA组抱团样发作总次数较母体IgG组明显增多（336次vs109次,P〈0.05）;NMDA组致症状评分为5.67分,母体IgG组为3.53分,差异有统计学意义（P=0.012）。母体IgG组抱团样发作潜伏期≥40min的比例为80%,NMDA组为32%,差异有统计学意义（P=0.022）。②NMDA组FOS蛋白阳性细胞呈弥漫性分布,其中以皮质、梨状皮质、海马和丘脑表达最多,染色深,其中皮质Ⅰ-Ⅴ均可见大量的FOS蛋白阳性细胞。母体IgG组FOS蛋白阳性细胞在以上各个脑区表达普遍减低。结论NMDA组FOS蛋白阳性细胞呈弥漫性分布、色深,其表达是对损伤刺激的早期反应,乳鼠痉挛发作模型FOS蛋白表达和NMDA受体分布部位基本一致。皮质、丘脑和海马、梨状皮质等边缘系统可能是NMDA诱导痉挛发作的主要结构。母体IgG具有抗痉挛作用,并可脑内使FOS蛋白表达降低。

Effects of maternal immunoglobulin G in infant rats with NMDA-induced spasms and the expressions of FOS protein in neurocytes

Objective Infantile spasms is an age-dependent expression of a damaged brain. The term ＂infantile spasms＂ has been used to describe the seizure type, the epilepsy syndrome. The traditional medical treatment of West syndrome has not changed for many years. A lot of new drugs were applied to this syndrome, but the effect was uncertain. High dose Immunoglobulin G and ACTH infusion were the main medical treatment methods. In our study, we investigated the protective effect of maternal immunoglobulin G on spasm activity and FOS protein expression in infant rats with NMDA-induced spasm. The purpose of this investigation was to determine the role of maternal immunoglobulin G in infantile spasm rat model.Methods Three female Wistar rats and 30 their neonatal rats were used. After giving birth, 8-10 mL blood was drawn from the three female Wistar rats. γ Globulin was abstracted from their blood, then was purified to get rat maternal Immunoglobulin G. Thirty neonatal rats were randomly divided into three groups： Control Group （n=6）： from postnatal days 11, normal saline injection was given subcutaneously at 8AM for five consecutive days and normal saline injection was given intraperitoneally one hour after the last subcutaneous injection. NMDA（N-methyl-D-aspartate） Group（n=12）：postnatal days 11, normal saline was also injected subcutaneously at 8AM for five consecutive days and NMDA （15 mg·kg^-1 was injected intraperitoneally at about one hour after the last saline injection; maternal immunoglobulin G Group（n=12）：From postnatal days 11, corresponding maternal immunoglobulin G （10 mg·kg^-1 was injected subcutaneously at 8AM for five consecutive days and NMDA （15 mg·kg^-1 injection was given intrapritoneally at 9AM after the last subcutaneous injection. All perfused brain tissues of rats were sectioned, and the c-fos expression was detected by immunohistochemistry staining on the 15th day in rat pups of the infantile spasm model. In neocortex, thalamencephalon, piriform cortex,dentate