摘要
目的 探讨在糖皮质激素诱导股骨头坏死过程中血管形态的改变与髓腔内脂肪填塞的关系。 方法 12～ 18个月龄的健康日本大耳白兔 5 2只 ,按 2 5mg·kg-1·d-1注射地塞米松建立股骨头坏死模型 ,通过血管铸型扫描电镜观察、墨汁灌注切片光镜观察及图像分析等方法观察用药中和停药后股骨头病理和血管形态的变化。 结果 用药 2周出现股骨头髓腔内脂肪填塞 ,窦状隙血管因脂肪细胞压迫变细 ,血管铸型、墨汁灌注切片显示了血管表面压迹。病变随用药时间的延长而加重 ,窦状隙血管逐渐失去其结构特征。图像分析示股骨头内血管面积进行性下降 ,8周约为对照组的1/ 4。停药 6周负重区髓腔内仍存在明显脂肪化 ,血管纤细、稀少。实验 4周 ,股骨头内出现典型骨坏死灶。随时间的延长 ,坏死灶增大、股骨头坏死程度加重。 结论 髓腔内脂肪填塞是导致糖皮质激素诱导性股骨头坏死中缺血损害的重要病理因素之一 。
Objective To evaluate the effects of fatty tamponade in medullary cavity (serious intramedullary fatty infiltration) on the changes of blood vessels in femoral heads during the pathological process of glucocorticoid(GC) induced avascular necrosis (AVM) of the femoral heads. Methods The animal model of AVN was established with injection of dexamethasone(DEX) at a high dose of 2 5 mg·kg -1 ·d -1 in rabbits. Histopathological and morphological changes of blood vessels in the femoral heads were investigated during GC treatment and after the cessation scanning electron microscope, light microscope, and image analysis. Results At the 2nd week of DEX treatment, the fatty tamponade in the medullary cavity appeared in the femoral heads. Intramedullary vascular sinusoids were pressed by an excess of lipocytes and became narrow.The impressions of lipocytes on the surface of vascular sinusoids were definitely displayed on the vascular casts and ink perfused slides of the femoral heads. These changes were pronounced with the prolongation of the treatment and the vascular sinusoids gradually lost their characteristics.Image analysis showed that the vascular area in the femoral heads continuously decreased.At the 8th week, the effects of fatty tamponade were the most marked. Intramedullary vessels became very sparse and the vascular area decreased to 1/4 of the controls. At the 6th week after the GC treatment cessation, intramedullary fatty infiltration still existed. The blood vessels were fine and sparse, and the structural features of vascular sinusoids disappeared in the load bearing regions of the femoral heads. At the 4th week, typical osteonecrosis focuses appeared in the femoral heads. The focuses became larger and the degree of osteonecrosis was increasing with the time of experiment. Conclusion The fatty tamponade in the medullary cavity is one of the important pathological factors causing ischemic damage to the femoral heads, and plays an important role in the early stage of GC induced AVN.
出处
《中华外科杂志》
CAS
CSCD
北大核心
2000年第3期212-215,I013,共5页
Chinese Journal of Surgery
基金
重庆市应用基础研究项目 !(193)
