Research in the precaution of recombinant human erythropoietin to steroid-induced osteonecrosis of the rat femoral head.

Objective To elucidate the effects of recombinant human erythropoietin (rHuEPO) on steroid-induced osteonecrosis of the femoral head in rats. Methods Twenty-four adult Wistar rats were randomly divided into three groups of eight rats each. The rats in the positive control group were injected with dexamethasone at 1 mg/kg twice a week for 5 weeks. The rats in the negative control group were injected with sodium chloride alone. The rats in the experimental group were injected with dexamethasone at 1 mg/kg twice a week for 5 weeks and rHuEPO (500 u/d/kg) daily for 5 weeks. The femoral head on one side was examined by hematoxylin and eosin staining, and that on the other side was examined by CD31 staining of the capillaries. Results Hematoxylin and eosin staining in the positive control group showed that the bony trabeculae had become obviously narrow and sparse with discontinuity of the integrity. The integrity of the trabeculae was better in the experimental group than positive control group. The CD31 expression was lower in the positive control group than in the other two groups. Conclusion rHuEPO can effectively prevent osteocyte apoptosis, delaying or decreasing osteonecrosis of the femoral head.