血管内皮生长因子在脊髓空洞前状态中的表达及作用机制探讨

Expression of vascular permeability factor/vascular endothelial growth factor in presyrinx state of experimental syringomyelia in rabbits and mechanism of action

目的 通过观察脊髓空洞前状态中脊髓水肿程度和组织学变化 ,测定血管内皮生长因子的表达并探讨其作用机制。方法 常规组织学及电镜观察 ,应用干湿法测定脊髓空洞前状态中脊髓含水量 ,ELISA和免疫组织化学测定脑脊液和脊髓中VEGF表达含量。结果 组织学观察发现 ,Kaolin组动物在术后 2周内出现脊髓水肿且随时间延长逐渐加重 ,2 1d出现髓鞘和轴索损伤 ;脊髓含水量较对照组在术后第 1天轻度升高 (68.3 5± 0 .70 ) % ,第 3天水肿明显加重 (72 .70± 0 .88) % ,第 7、14天达到高峰 [(72 .92± 0 .86) %、(72 .18± 0 .5 5 ) % ] ,第 2 1天水肿开始缓解 ,但仍高于正常 (70 .0 3± 0 .77) %。Kaolin组动物脊髓、脑脊液中VEGF表达较正常对照明显增高 ,其强度变化趋势与脊髓水肿和组织学变化程度一致。结论 在实验性脊髓空洞症模型中 ,缺血水肿 ,组织含水量增高构成脊髓空洞前状态的主要表现 ;VEGF高表达在脊髓空洞前状态中的水肿形成中起重要作用。

ObjectiveTo estimate spinal cord edema degree and patho-morphology of presyrinx state of experimental syringomyelia and observe its development tendency;To investigate the role and mechanism of VEGF in the formation of presyrinx state of experimental syringomyelia in rabbits.MethodsThe experimental syringomyelia models of rabbits were established by intra-cisternal injection of kaolin.Histological and electron microscopic examinations were carried out.Water content of spinal cord (%) was measured by dry-wet technique,and the VEGF expression intensity in cerebral spinal cord fluid of control and Kaolin group was detected by Enzyme-linked immunoadsorbent assay (ELISA) and immuno-histochemistry.ResultsHistological investigation revealed that the spinal cord edema occurred over time in Kaolin group 2 weeks after operation.At 21th day,myelinoclasis and axonal lesion were seen.Comparing with control group (70.03±0.77)%,water content of spinal cord in Kaolin group was slightly increased at the 1st day (68.35±0.70)% after Kaolin injection,significantly elevated at 3rd day (72.70±0.88)%,reached peak at 7th and 14th day [(72.92±0.86)% and (72.18± 0.55)% respectively],and declined slowly at 3rd week (70.03±0.77)%.In the Kaolin grouo,the VEGF expression in spinal cord and cerebral spinal cord fluid was significantly increased as compared with control group,with its intensity tendency coinciding with that of spinal cord edema degree and histological changes.ConclusionIn the models of experimental syringomyelia,the main disorders of presyrinx state inculded angiotic edema at earlier stage and interstitial edema at later stage.The overexpression of VEGF plays a major role in the formation of presyrinx state.