猫小脑髓质胶质反应的年龄相关性变化

Age-related changes of gliosis in cerebellar medulla of cat

探讨青年猫和老年猫小脑髓质中胶质反应的年龄相关性变化及其意义。用改良的Holzer结晶紫染色显示所有胶质细胞,GFAP(胶质纤维酸性蛋白)免疫染色显示星形胶质细胞。光镜下对青年猫与老年猫小脑髓质中胶质细胞和GFAP免疫阳性(GFAP-IR)星形胶质细胞进行形态学观察和定量研究。与青年猫比较,老年猫小脑髓质中胶质细胞和GFAP-IR细胞密度均显著增加(P<0.01),胞体较大;GFAP阳性细胞阳性反应较强,突起稠密;星形胶质细胞占胶质细胞总数比例增加。这表明小脑髓质中胶质细胞随年龄增长明显增生,尤其星形胶质细胞具有明显的年龄相关性活动增强。提示胶质细胞及星形胶质细胞的增生可能对衰老的神经纤维起保护作用;星形胶质细胞对衰老较敏感。

To detect age -related changes of gliosis in cerebellar medulla of young adult and old cats, the modified showed Holzer stain was used to display all the glail cells. The shape of GFAP - immunoreactive （ GFAP - IR） by immunohistochemical ABC method to labeled astrocytes. Under microscope the density of glial cells as well as the GFAP - IR cells was calculated. Compared with young adult cats, the old cats had a significant increase in the density of the total glial cells and the astrocytes （P 〈0.01 ）. At the same time, the astrocytes in old cats showed larger in the size, stronger in the immunoreaction of GFAP and occupied a larger proportion among the total glial cells than the young adults. The above results suggested that the old cats had significantly age - related hyperplasia of glial cells and a special activity enhancement of astrocytes in the medulla, which meight exert protective effect on degenerative nerve fibres. The GFAP - IR cells occupying a larger proportion in the total glial cells in old cats suggestsed that astrocytes were more sensitive to ageing than the other glial cells.