S100和GFAP在猫上丘表浅层表达差异的免疫组织化学观察

AN IMMUNOHISTOCHEMICAL OBSERVATION OF DIFFERENTIAL EXPRESSION OF S100 AND GFAP IN THE SUPERRICIAL SUPERIOR COLLICULUS OF CATS

目的比较青、老年猫上丘表浅层(superricial Superior Colliculus,sSC)星形胶质细胞中S100蛋白与胶质原纤维酸性蛋白(glial fibrillary acidic protein,GFAP)表达的老年性变化,并探讨其在动物视觉功能衰退中的意义。方法采用免疫组织化学方法(SABC法)示青、老年猫上丘表浅层S100免疫阳性反应(S100-immunoreactive,S100-IR)细胞及胶质纤维酸性蛋白免疫反应阳性(GFAP-immunoreactive,GFAP-IR)细胞。光镜下观察、拍照,并利用Image-ProExpress图像分析软件对上丘表浅层各层S100和GFAP免疫反应阳性细胞密度及其灰度值进行测量。结果与青年猫相比,老年猫上丘表浅层中S100蛋白与GFAP表达均有不同程度的显著增强(P<0.01)。结论衰老进程中,上丘表浅层出现S100、GFAP表达增强,星形胶质细胞存在明显的反应性活化与增生,这对维持上丘表浅层神经元的活性和神经元之间的通讯联系,从而延缓老年性视觉功能衰退具有重要意义。

Objective To comparatively investigate aged changes in the expressions of S100 protein and glial fibrillary acidic protein in the superficial Superior Colliculus astrocytes of young and old cats, and to discuss the meaning of visual function degeneration during senescence underlying these changes. Methods We applied an immunohistochemical method to exhibit the S100 immunoreactive （S100-IR） and GFAP immunoreactive （GFAP-IR） cells. Under light microscope, the density of the S100 and GFAP immunoreactive cells, and their gray value were counted respectively with Image-Pro Express Software 5. 1. Results Compared with those of young cats, the density and average grey value of S100 and GFAP immunoreactive cells both increased significantly to different degrees in the superricial Superior Colliculus of old cats （P〈0. 01）. Conclusion The expressions of S100-IR and GFAP-IR in old cats are stronger than those in young cats. With age, astrocytes in the superficial superior colliculus are significantly activated and increased, which is of great significance in maintaining normal neuronal activities, signalling between neurons and therefore slowing down age-dependent vision function degradation.