脑内移植时星状胶质细胞的变化

THE CHANGES OF ASTROCYTES DURING INTRACEREBRAL TRANSPLANTATION

本文用胶质纤维酸性蛋白免疫组织化学方法研究了帕金森氏病模型鼠、老年性痴呆模型鼠及皮质损伤鼠等在脑移植２～３个月后移植区及其与宿主交界面的胶质细胞变化。结果发现不同动物模型的胚脑移植区及其与宿主交界面的胶质变化基本相同．Ｎｉｓｓｌ染色切片上可见移植区和宿主之间有直径小于８μｍ的小细胞集聚。胶质纤维酸性蛋白免疫组织化学法发现移植区和宿主脑交界面有深染的阳性纤维及细胞或交界面形成一包膜状结构；还有的在交界面无明显的胶质纤维酸性蛋白阳性纤维分隔，呈现两者相互融合的趋势．移植区内可见两种胶质细胞，一种与正常胶质细胞近似，另一种为胞体大、突起粗且深染的反应性胶质细胞；移植区内的血管周围也见有反应性胶质细胞包绕。本研究表明移植也可引起胶质反应，并且移植区内反应性胶质细胞可能对植入的神经元提供其生存所需要的营养物质。

Employing glial fibrillary acidic protein(GFAP) immunocytochemistry method we examined the astrocytic changes in the graft area and the interface between graft (G) and host (H) of parkinsonism rats, Alzheimer's disease rats and frontal cortex lesioned rats at 2～3 months after intracerebral grafting. Nissl staining in most cases revealed an accumulation of dense homogenous small cell(<8μm) which formed a layer on the border of the transplant. GFAP staining revealed that the changes of astrocytes in the graft area and the region of interface are similar to each other in different type of diseased rats. At the host-graft border we found: 1. that the heavily stained GFAP fibers and cells were located at the transplantshost border; 2. that in some of the animal brains GFAP positive fibers formed a capsule surrounding the boundary of the graft; 3. that in a few animals very few GFAP stained fibers were seen in the region of host-graft border indicating a tendency of integration. Within the transplants there were two types of astrocytes. One type is reactive astrocyte with hypertrophy cell body and heavy GFAP stained processes, and the other is similar to normal astrocyte. Besides, the hypertrophyed reactive astrocytes were also seen around the blood vessels in the transplants. Our study suggests that neural transplantation caused injury in the host brain may induce gliosis and that reactive astrocytes in the graft may play an important role for supplying the neurotrophic factors to neurons.