激素性股骨头缺血性坏死动物模型诱导

INDUCTION OF ANIMAL MODEL OF ISCHEMIC NECROSIS IN FEMORAL HEAD WITH STEROIDS TREATMENT

目的：诱导激素性股骨头缺血性坏死标本，为实验和临床研究提供满意的动物模型。方法：选中国大白兔３４只，随机分为４组。Ａ组：１０只，静脉内注射大肠杆菌内毒素，共２次，间隔２４ｈ。Ｂ组：１０只，注射内毒素同Ａ组，在第２次注射完大肠杆菌内毒素后随即肌肉注射甲基强的松龙，共３次，间隔２４ｈ。Ｃ组：１０只，单纯肌肉注射甲基强的松龙，共３次，间隔２４ｈ。Ｄ组：４只，对照组。将动物在最后一次注射后１ｍｏ处死，取股骨头标本，做组织学检查。结果：光学显微镜证实，在Ｂ组中，出现了较为典型的骨坏死，表现为骨小梁、骨髓坏死及髓腔内出血，骨内微循环有明显血栓或脂栓形成。透射电镜证实在Ｂ组中，骨细胞明显溶解坏死。结论：皮质类固醇激素能增加细菌内毒素反应导致明显高凝血状态及骨坏死。主要是造成了骨内外血管内皮损害，加重了内毒素引发的高凝血状态从而继发血栓形成，引起骨细胞的缺血性损害。表明在系统高凝血状态下应用激素。

Objective:To induce the specimen of ischemic necrosis in adult rabbits femoral head and to develop a satisfied animal model for clinical and experimental study.Methods:34 adult China white rabbits were divided into 4 groups.In group A,10 rabbits were given endotoxin from Escherichia intravenously 2 times at an interval of 24 hours.In group B,10 rabbits were given endotoxin as in group A and were injected intramuscularly with methylprednisolone 3 times at intervals of 24 hours after the second injection of endotoxin.In group C,10 rabbits were given methylprednisolone intramuscularly 3 times at intervals of 24 hours.In group D,4 rabbits were used as the control.All of the rabbits were killed at 1 month after their final injection.Results:For light microscopic examination,the typical osteonecrosis were found in group B,the trabeculae or marrow necrosis were evident with apposition bone formation ,and there were also apparent thrombosis in the intraosseous microcirculation.For transmission electron microscopic examination,clear cell necrosis or cytolysis of bone were found in group B.Conclusion:Exogenous steroid appeared to potentiate the endotoxin reaction and the magnitude of hypercoagulability and osteonecrosis.It mainly increase the endothelial damage and hypercoagulability of those intraosseous and extraosseous vessels that subsequently thrombosed,cause the ischemic damage of femoral head.These results apparently indicated that,in the state of hypercoagulation,osteonecrosis was easy induced after steroid administration.