[Expression of nestin and glial fibrillary acidic protein in injured spinal cord of adult rats at different time].

OBJECTIVE: To explore the expression of nestin and glial fibrillary acidic protein (GFAP) at different time and sites after spinal cord injury in adult rats.

METHODS: Seventy-two adult Sprague-Dawley rats, aging 8 weeks and weighing from 180 to 220 g, were randomly divided into 11 experimental groups (66, n=6) and 1 control group (n= 6). In the experimental groups, the rat spinal cord injury models were established by aneurysm clip compression, and the expression and proliferation of nestin and GFAP at different time (1 day, 3 days, 5 days, 1 week, 2 weeks, 3 weeks, weeks, 5 weeks, 6 weeks, 7 weeks and 8 weeks) and at different sites (injured site and adjacent site) were observed with toluidine blue staining, immunofluorescent staining and the analytical system of photographs. In control group, the same site of the rat spinal cord was exposed without aneurysm clip compression. The same preparation and examination were done as the experimental groups.

RESULTS: Toluidine blue staining results showed that contour of neurite and pericaryon were distinct and nucleus were deep blue in normal control rats. One day after injury, the number of big and medium-sized neuron decreased obviously; neurite was deep blue with clouding Nissl bodies and ellipse or triangular typed nucleus. In the normal control group, the expression of nestin was hardly seen except ependymal cells of central canal, and the low expression of GFAP was seen. In the experimental groups, the nestin and GFAP expressions increased obviously in the injured sites and adjacent sites 24 hours after injury, reached the peak value after 3-7 days and followed by gradual decrease. There were statistically significant differences in the nestin and GFAP expressions between the experimental groups and the control group.

CONCLUSION: The above results suggest that spinal cord injury can induce the expression of nestin and GFAP. There is a positive correlation between nestin expression and the proliferation of the reactive astrocytes.