摘要
Abstract
Objective To investigate the expression of platelet-derived growth factor (PDGF) in astrocytes after acute contusive spinal cord injury (SCI) in diabetic rats. Methods Twenty four hours and 7 days after SCI, the motor function of rats was evaluated by BBB score, pathological changes of spinal cord was observed by light microscopy, PDGF expression in astrocytes was examined by immunohistochemistry and Western Blot. The number and optical density of the PDGF-positive cells were determined by UTHSCSA Image Tools 3.0. The expression levels of PDGF were measured by BIO-RAD software Quantity. Results The rats of SCI suffered from paraplegia, severe motor dysfunction 24h after injury. There was no significant difference in BBB function scores between the spinal cord injury group and diabetic spinal cord injury group (P ＜0.01). The rats in spinal cord injury group restored 7-8 points, whereas diabetic spinal cord injury group were slowly recovered, BBB function score was ranged from 3-4 point (P ＜0.01), sham surgical control group moved freely without any dysfunction, postoperative 24h and 7d score were 21 points (P ＜0.01). The structure of neurons and astrocytes was clear and integrity in the normal rats' gray matter. After 24h injury,many swollen axons and a large number of vacuoles existed in the white matter of spinal cord injury group and diabetic spinal cord injury group, and there was also very small amount of neurons and astrocytes presenting in the gray matter. The scope of injury had been determined and the cavity had formatted in the spinal cord by 7d post-injury, which was in diabetic spinal cord group bigger than in spinal cord group, and the region of injury was surrounded by inflammatory. PDGF expressed little in normal group'astrocytes after operation. The expression of PDGF was increased in spinal cord injury group and diabetic spinal cord injury group at 24h after SCI, but compared with diabetic spinal cord injury group, the expression level of PDGF was higher(P ＜0.01).After 7d, PDGF was sustained expressing in spinal cord injury group, and there was significantly difference compared diabetic spinal cord injury group (P ＜0.01). To confirm this observation, we also detected PDGF expressing in the three groups. Compared with diabetic spinal cord injury group, the expression of PDGF was significantly higher in spinal cord injury group at 24h and 7d post-injury, respectively(P ＜0.01). These results were consistent with the result of immunohistochemistry. Conclusion 1. BBB score was significantly lower in diabetic spinal cord injury group than that of spinal cord injury group in rats at 7d post-injury.2. The expression of PDGF was also significantly reduced in diabetic spinal cord injury group compared with spinal cord injury group, it may be related to inhibit of resumption of SCI at the hyperglycaemia condition.关键词
脊髓损伤/糖尿病/血小板衍化生长因子/大鼠
