甘珀酸对癫痫大鼠前脑connexin-32和GFAP表达研究

目的研究大鼠在脑室埋管注射甘珀酸(CBX)预处理后戊四氮导致癫痫发作时前脑内胶质纤维酸性蛋白(GFAP)和连接蛋白-32(Cx32)表达及其相互关系. 方法动物分为生理盐水(NS)对照组(NS组)、CBX预处理对照组(CBX组)、戊四氮(PTZ)致痫组(PTZ组)、CBX预处理后再PTZ致痫组(CBX PTZ组),应用免疫荧光组织化学双重标记显示GFAP和Cx32在前脑的表达及其相互关系.结果 CBX PTZ组的大鼠癫痫发作的行为表现比PTZ组显著加重,星形胶质细胞GFAP的表达也比PTZ组明显升高,值得注意的是CBX组的星形胶质细胞GFAP的表达比NS组明显升高.Cx32在PTZ引起的癫痫大鼠的大脑皮层、海马和杏仁核内是增加的,而CBX预处理后的癫痫模型中Cx32却降低了.在Cx32与GFAP双标的切片上发现,Cx32与GFAP阳性的星形胶质细胞非常接近,在CBX预处理后的癫痫模型中GFAP阳性的星形胶质细胞显著增加的同时Cx32却明显降低. 结论在整体动物CBX预处理可以导致癫痫发作增强,这可能与星形胶质细胞增生及其Cx32表达降低有关.

Research of carbenoxolone on expression of connexin-32 and GFAP in forebrain of epileptic rats

Objective To observe the expression of connexin-32 and glial fibrillary acidic protein (GFAP)and their mutual relationship in forebrain of pentylenetetrazol (PTZ) induced seizure in rats after pretreatment with carbenoxolone (CBX).Methods The animals were divided into normal saline(NS), CBX, PTZ and CBX PTZ group. The double-labeled fluorescence immunohistochemical staining for anti-GFAP and anti-connexin32 was used to investigate the expression and relation of GFAP positive cells and connexin 32 protein.Results The behavior of seizure in CBX PTZ group was more serious than that in PTZ group, and the expression GFAP in CBX PTZ group was also intensified obviously. Noticeably, the expression of GFAP in CBX group was much higher than that in NS group. The distribution of Cx32 in cortex, hippocampus and amygdaloid nucleus increased in PTZ-induced epileptic rats, but Cx32 decreased in CBX PTZ group. On the slices with anti-Cx32 and anti-GFAP double-labeled, anti-Cx32 positive production was close to anti-GFAP positive astrocytes. The GFAP positive astrocytes increased obviously, but the expression of Cx32 decreased in CBX PTZ group.Conclusion The present results indicate that epilepsy enhancemented by CBX pretreatment may be related to astrocytic hyperplasia and the decreased expression of Cx32 protein.