VEGF在高压氧治疗激素性股骨头坏死中的意义

目的:观察血管内皮生长因子(VEGF)在激素性股骨头坏死及高压氧治疗过程中的变化,探讨激素性股骨头坏死的发病机理。方法:健康日本成年大耳白兔60只,随机分为模型组(n=42)及对照组(n=18)。模型组每周两次肌肉注射醋酸泼尼松龙10mg/kg,对照组每周两次肌肉注射生理盐水2ml。共6周。随后将模型组随机分为高压氧治疗组(n=16)及常压常氧组(n=16),前者行高压氧治疗,后者呼吸常压新鲜空气,共持续6周。检测实验第2周、4周、6周、8周、10周、12周各组兔骨组织VEGF表达、组织病理学及影像学变化。结果:造模第6周时股骨头较多骨细胞坏死溶解成碎片,股骨头软骨下区骨小梁表面的成骨细胞和血管仅出现少量VEGF阳性表达;高压氧治疗第6周,实验兔骨小梁周围出现较稀疏的骨母细胞,电镜发现新生的骨细胞和胶原纤维,VEGF阳性细胞明显增多,软骨下阳性血管也明显增多,阳性部位主要位于血管内膜,同时在染色阴性区域出现点状新生毛细血管。结论:高压氧通过促进VEGF等细胞因子的分泌,加速股骨头的再血管化和再骨化进程,促进骨修复。

Significance of Vascular Endothelial Growth Factor in Steroid-induced Vascular Necrosis of Femoral Head Treated with Hyperbaric Oxygen

Objective:To investigate changes of vascular endothelial growth factor(VEGF) in the mode of steroid-induced avascular necrosis of femoral head(SANFH) and treated with hyperbaric oxygen,and to explore the pathogenesis of SANFH.Method:60 adult Japanese rabbits were randomly devided into two groups:experimental group(n=42) and control group(n=18).As for experimental group,each rabbit injected with massive dose of prednisolone acetate(10mg/kg) two times per week.and as for control group,injected with 2ml of salt water,lasted for six weeks.Then,rabbits in experimental group were randomized divided into hyperbaric oxygen (HBO) group(n=16)and normoxic group(n=16).The HBO group received HBO treatment for 6 weeks and normoxicl group was placed in the fresh air.At the end of 2,4,6,8,10,12 weeks,the ratio of VEGF,pathological changes of femoral head in light microscope and electron nicroscope,imaging changes were observed.Results:At the end of 6th week,a propotion of osteocytes decreased in volume and the nuclei shrunk in the experimental group.Many osteocytes underwent necrosis,dissolved and became fragments.The masculine expression of VEGF was slight.At the end of 6th week in HBO group,scattered osteoblast cells could be observed around the bone trabecula.Nascent bone cells and collagenous fibri could be found by electron microscopy.The ratio of masculine cells of VEGF,which were mainly in the endangium,was increased obviously.At the same time,there were many newborn micrangium.Conclusion:HBO can accelerate the vascular developing and ossification by promoting the exudation of VEGF and enhanced bone repairing.