RESUMO
Objective To explore the effects of gossypol acetate on the morphological features and the gene expression in the femoral head of Sprague-Dawley rat in vivo after treated with dexamethasone .Methods Dexamethasone(Dex) was injected into the abdominal cavity of SD rats at an dose of 10 mg/kg ,twice a week ,and feed gossypol acetate 5 mg · kg -1 · d-1 .The controls re-ceived saline 2 mL injection .The treatment lasted for 12 and 20 weeks .The slices of the femoral head were made for HE and immu-nohistochemical study .The total mRNA was extracted for RT-PCR assessment .Results The cancellous bone trabecular became sparse ,trabecular bone area ratio decreased ,bone marrow fat tissue increased .These changes were fitted for pathological character of bone necrosis .The gossypol acetate could not affect the pathological changes .The proportion of the positive stained osteoblasts increased ,adipocytes decreased .PPARγ,C/EBPα,11β-HSD1 expression enhanced ,Runx2 down regulated in the treatment groups and GAA group .Conclusion Dex can induce evident pathological changes conform to the characters of femoral head necrosis .They may have closed correlation between 11β-HSD1 and the gene expression .But GAA could not affected the pathological changes and abnormality of the gene expression .