Expression of glucocorticoid receptor in steroid-induced juvenile rabbit model of avascular necrosis of the femoral head and its significance / 中华实用儿科临床杂志

ABSTRACT

Objective To detect the expression of glucocorticoid receptor(GR) in juvenile rabbit modal of avascular necrosis of the femoral head,and explore the possible etiology of avascular necrosis of the femoral head in children.Methods Sixty New Zealand albino rabbits(50％ female and 50％ male),2 months old,body weight 1.4-1.7 kg,were randomly divided into 2 groupssteroid injection group (SIG) and control group(CG).The SIG(n =48)Prednisolone acetate of 7.5 mg/kg was injected into each rabbit twice a week for 8 weeks.The CG(n =12)9 g/L saline of 0.3 mL/kg was injected into each rabbit twice a week for 8 weeks.The immunohistochemistry and image analysis were used to detect the expression of GR.The SIG was divided into disease group(DG) and non-disease group(NDG).The expressions of GR were compared among DG,NDG and CG.Results In the 8th week after the first injection in SIG,31 out of 48 rabbits survived,and 7 out of 31 rabbits(22.85％) developed femoral head avascular necrosis.GR expression in DG was 100.00％ (7/7 cases),while in NDG and CG they were 20.83％ (5/24 cases) and 16.67％ (1/6 cases).Significant difference was found between DG and NDG/CG(all P ＜ 0.01),but not between NDG and CG.GR expression density in femoral cartilage in DG was higher than in NDG and CG(all P ＜ 0.01).GR expression IOD in femoral cartilage was 7942.21 ± 1886.94,but in DG and NDG they were extremely low or undetectable,which were 627.56 ± 281.85 and 571.48 ± 260.22,separately,and there was significant difference (all P ＜ 0.01).Conclusions Simple gluteal injection of glucocorticoid can lead to juvenile rabbits avascular necrosis of femoral head.GC and GR might play an important role in the onset and development of avascular necrosis of femoral head in juvenile rabbits.