激素性股骨头缺血坏死与血管壁中主要促血管生长因子生理活性关系的实验研究

Effects of major angiogenesis stimulating factors （PDGF and VEGF） on steroid treated blood vessel wall

目的探讨激素性股骨头缺血坏死与受激素影响的血管内膜层中血小板源性生长因子（PDGF）生理活性及血管内皮生长因子（VEGF）mRNA表达发生变化的关系。方法选中国大白兔40只，随机分成三组，A组：15只，为模型组，静脉内注射大肠杆菌内毒素及肌肉注射甲基强的松龙；B组：15只，单纯注射大肠杆菌内毒素；C组：10只，为健康对照组。取支配股骨头血运的主要血管（旋股内侧动脉、股静脉）及股骨头，制成标本。应用组织学、免疫组化、原位杂交进行观察检测。结果A组动、静脉内膜层中PDGF-A＋B／PDGF-α＋β表达分别为0．4341±0．0397、0．3505±0．0407，A组动、静脉内膜层中VEGF mRNA表达分别为0．2550±0．0297、0．2061±0．0371。A组动、静血管内膜层中PDGF生理活性及VEGF mRNA表达与股骨头发生坏死的程度呈明显负相关，具有统计学意义（动脉中r=-0．808，P〈0．01；r=-0．312，P〈0．01。静脉中r=-0．842，P〈0．01；r=-0．825，P〈0．01）；B、C组则不存在上述统计学结果。结论激素可导致PDGF生理活性相对下降以及VEGF mRNA转录下调，进而影响PDGF与VEGF对血管生成的正常调节，是激素导致股骨头坏死的重要病理学基础。

Objective To detect the relationship between steroid-induced necrosis of the femoral head and changes of PDGF and VEGF mRNA in steroid-affected vascular endothelium. Methods Forty adult China white rabbits were randomized into 3 groups. In group A, 15 rabbits were given endotoxin and methylprednisolone. In group B, 15 animals were given endotoxin. Ten rabbits in group C served as controls. The main blood vessels to the femoral head （the medial femoral circumflex artery and femoral vein） and the femoral head were used for specimen preparation under the state of relative asepsis and non-RNA-enzyme. Specimens were observed by examinations of histology and immunohistochemistry and in situ hybridization. Results In group A, examinations showed a significant negative correlation between either the function of PDGF or the expression of VEGFmRNA and necrosis of femoral head in the vascular wall （in artery r = - 0.808, P 〈0.01; r= -0.312, P 〈0.01 in vein r= -0.842, P 〈0.01; r= -0.825, P 〈0.01） . There was no such significant discrepancy in groups B and C. Conclusion It may be the key pathological basis of steroid-induced necrosis of the femoral head that steroid reduces the function of PDGF and inhibits the transcription of VEGFmRNA, fianally affecting their normal adjustment on angiogenesis.