Objective: To explore the expression of apoptosis factor in rat models of steroid-induced femoral head necrosis.
Methods: 90 SD rats were randomly divided into the control group and the model group. The rats in the model group were treated with 12.5 mg/kg prednisolone by intramuscular injection for twice a week to prepare the models of femoral head necrosis, while the control rats were injected with the same dose of saline with the same injection time as the model group. The rat femoral heads were obtained in 4, 8, and 12 weeks after injection, and then stained by haematoxylin eosin to observe the bone tissue morphology. The expression of Bcl-2 and Caspase-3 were determined by immune-histochemical staining and analysed for the correlation between the two ones.
Results: Through microscopic observation, it is found that the model rats were successfully prepared. The expression of Caspase-3 protein in the model group was significantly higher than that in control group (P<0.05), and the longer the modelling time, the more obvious difference between the two groups; The expression of Bcl-2 in model group was significantly lower than that in control group (P<0.05); After Spearman rank correlation analysis, the expression levels of Bcl-2 and Caspase-3 were not correlated.
Conclusion: Hormones can improve the expression of Caspase-3 to make the apoptosis of the femoral head, and reduce the anti-apoptotic effect of Bcl-2, so that lead to the necrosis.