| Object:Study injection of glucocorticoid, while comibination treament with Simvastatin and Lumbrokinase can reduce the degree of Steroid-induced Necrosis of Femoral Head in Rabbits(SNFH) or reduce its incidence, and to discuss its treatment mechanism.Methods:48 healthy adult New Zealand white rabbits were randomly divided into threegroups:treatment group (group C n=16),model group (group B n=16) and normal group (groupAn=16). After being weighted, every rabbit of B,C groups was injected horse serum with 10 ml/kg via rabbit ear vein. After 2 weeks, rabbits of B,C groups were injected horse serum with 5ml/kg/d for two consecutive days. Interval of 2 weeks, B,C groups were injected methylprednisolone with 40mg/kg/d through intra-abdominal injection straightly for three days. And the normal group were injected the same amount of saline for three days. During these weeks,on every Monday,Thursday each rabb it was injected penicillin 100,000U one time to prevent infection.And from the first injection of methylprednisolone, the C group were given simvastatin 10 mg/kg/d and Lumbrokinase 30000 u/kg/d by gavages till they were killed. A, B groups were given the equal volume of distilled water. After the injection of glucocorticoid at the last 6 weeks,12 weeks in each group randomly selected from eight rabbits air embolization were killed, and bilateral femoral head, generally observed, HE staining, vascular endothelial growth factor (VEGF) immunohistochemical staining.Results:(1)general observation:â‘ Rabbits'body weights of normal group gradually increased. The appearances of the femoral heads took a full look.The bones were hard,and not easy to sliver.â‘¡Rabbits'body weights of model group had been declining.The appearances of the femoral heads looked no significant deformation, collapse, but the surface colors were darker.And the femoral heads were so crisp that easy to slice.â‘¢The rabbits'body weights of treatment group decreased gradually before the rebound. The appearances of femoral heads looked undeformed, the surfaces were still shiny.Compared with model group, the resistances of slicing the femoral heads was larger. (2) Histopathological observation:The rules of subchondral trabecular bone of normal group arranged neatly, dense.The bone cells, clearly visible;the nuclear were large, multi-located in the center, occasionally empty lacunae, on the 12th week, there were no significant changes.The subchondral trabecular bone of model group were thinning, the spaces were larger, the structural were disorder,and some have the phenomenon of bone cell broken. The nuclears margined, condensed.The empty lacunae increased.Both the number and the volume of the fat cells increased. On the 12th week, the changes on the above became seriously. The trabecular bones of treatment group were large and coarse, bone nucleus as normal, marrow fat cells within the rare few empty lacunae. On the 12th week, they were close to normal group. (3)VEGF immunohistochemical results:on the 6th and 12th week, the expression of VEGF was positive in normal group. There were no significant different expressions between the two time points(P>0.05). Compared with the normal group, the expression of VEGF in model group was reduced at 6th week(P< 0.01). The expression of VEGF become weaker at 12th week. Compared with model group,the expression of VEGF in treatment group increased at 6th week. The difference was significant (P<0.01).At 12th week,the expression of VEGF in treatment group significantly increased(P<0.01).Conclusion:The combination treament with Simvastatin and Lumbrokinase can reduce the degree of Steroid-induced necrosis of femoral head in rabbits and its incidence.It is a complex physiological and pathological process that takes the fat metabolism disorder and intravascular coagulation as the main pathogenesis and other pathological mechanism of the interaction. The combination of Simvastatin and Lumbrokinase increases the expression of VEGF of steroid-induced necrosis of femoral head. |
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