甲强龙联合内毒素诱导犬股骨头坏死的实验研究

目的建立使用1次低剂量内毒素联合连续3次高剂量甲强龙诱导杂种犬股骨头坏死模型,并观察所造成股骨头坏死的特点。方法动物模型组采用12个月龄中国健康杂种犬12只,先予犬静脉注射内毒素1次（9.0μg/kg）,24 h后连续3 d每天行甲强龙肌内注射（18.0 mg/kg）。空白对照组4只,腹腔内注射等量生理盐水。末次注射2、4、6周后2组均行双髋关节数字化X线（DR）、磁共振成像（MRI）及病理组织学检查（Masson染色）。结果末次注射2周后动物模型组所有检查均未发现股骨头坏死的征象,4周后动物模型组Masson染色出现早期骨坏死表现,6周后动物模型组MRI及Masson染色出现较明显的早期股骨头坏死表现。结论采用1次低剂量内毒素联合连续3次高剂量甲强龙注射可造成杂种犬股骨头坏死模型。

Experimental study of avascular necrosis of femoral head of dogs induced by methylprednisolone and endotoxin

Objective To observe the characteristics of the avascular necrosis of femoral head of mongrel dogs caused by using a single low-dose lipopolysaccharide（LPS） injection and subsequently three injections of high-dose methylprednisolone（MPS）. Methods Twelve 12-month-old Chinese mongrel dogs received one intravenous injection of LPS（9.0 μg/kg）. Twenty four hours later, three injections of MPS（18.0 mg/kg） were given in tramuscularly at a time interval of 24 h. Additional 4mongrel dog injected with the same amount of saline solution in the abdominal cavity was used as the control group. Two,four,six weeks after the last injection, the model group and control group were performed by digital X-ray（DR） and magnetic resonance imaging（MRI）, and the femoral head of the model groups were removed for histopathologic examination（Masson staining） in 2, 4, 6 weeks respectively. Results After 2 weeks, the model group underwent DR, MRI and Masson staining.There was no signs of osteonecrosis. After 4 weeks, the evidence of osteonecrosis were not found in the model group by DR and MRI. But early osteonecrosis was found in Masson staining. After 6 weeks, osteonecrosis was not found in the model group by DR. But more apparent early osteonecrosis was observed in MRI and Masson staining. Conclusion A single low-dose LPS injection and subsequent three injections of high-dose MPS could cause the model of the avascular necrosis of femoral head of mongrel dogs.