Effect Of Simvastatin On The Lipid Metabolism Of The Rabbits Having Steroid-induced Femoral Head Necrosis

Objective:By observing the change of blood lipids and hemorheology of the early steroid-induced femoral head necrosis caused by injecting hormone and simvastatin, furtherly explore the feasibility of simvastatin on the prevention against steroid-induced femoral head necrosis and its mechanism, and provide theoretical basis for the prevention and cure of steroid-induced femoral head necrosis.Methods:48 healthy adult New Zealand rabbits were randomly divided into:group A (control group:normal saline); group B (model group:horse serum+methylprednisolone); group C (intervention group:horse serum+methylprednisolone+simvastatin),16 each group.A:injection of equal normal saline; B, C:by precisly weighing, each injected with a horse serum 10ml/kg through rabbit ear vein,and after 2 weeks, each injected with a horse serum 10ml/kg for successive 2 weeks,and after 2weeks,each intraperitoneally injected with methylprednisolone 40mg/kg for successive 3 days (daily injection of 1).Each rabbit of group A was injected with equal normal saline for successive 3 days.For the prevention of infection, all animals were injected with penicillin 50000 U/time,1 and 4 During the week.While injected with methylprednisolone at the first time, group C.was given simvastatin 20mg/kg/d orally.A, B group with an equal volume of distilled water.After 6 weeks,12 weeks,each group was randomly selected eight for the detection and comparison of blood lipids and hemorheology,and then sacrificed,and after 6 weeks,12 weeks, take general and histological observation of femoral head.Results:(1) General observation:weight of the rabbits of group A increased,the femoral heads were integrity and smooth,cartilage surface was good,bone was hard; weight of the rabbits of group B decreased, the femoral head were more complete,but the cartilage surface lacked luster,occasionally coarse;weight of the rabbits of group C firstly decreased and gradually rebound, the femoral heads were more smooth and complete than group B.(2) histopathological observation:the rate of empty lacunae and fat cell size in the treatment group was significantly lower than model group (P<0.01); model group were significantly higher than control group (P<0.01); There was significant differences between the treatment and control group (P<0.01) (3) lipids:cholesterol,triglycerides in group B were significantly higher than in group A at 6 weeks and 12 weeks(P<0.01);group C was significantly lower than group B at the same time(P<0.01),group C wad significantly higher than group A after 12 weeks(P<0.01).(4)data of hemorheology:the high blood shear,low shear viscosity and plasma viscosity in group B at 6 weeks,12 weeks was significantly higher than group A(P<0.01); group C was significantly lower than group B at the same time(P<0.01),group C at 12 weeks was significantly lower than it at 6, weeks (P<0.01).Conclusion:By the using of high-dose methylprednisolone+horse serum in short term, we successfully create an model of early femoral head necrosis.Hormone and simvastatin injections can decreased the cholesterol, triglycerides and hemorheology detection of the animal models,but the indications did not completely return to normal till the end of the experiment, and further study is expected.