BILATERAL OVARIO-HYSTERECTOMY INDUCED OSTEOPOROTIC RABBIT MODEL

Abstract

Rabbit models have been proposed for the study of postmenopausal osteoporosis by bilateral ovariectomy with reduced dietary calcium intake or glucocorticoid administration. However, restricting dietary calcium intake or administering a glucocorticoid can cause secondary osteoporosis and is not representative of a pure postmenopausal osteoporosis model. The aim of this study was to establish an experimental rabbit model of osteoporosis induced by ovario-hysterectomy alone. Fourteen female New Zealand rabbits were separated into two groups of a sham (control) group and an ovario-hysterectomyinduced osteoporosis group. Tibiae were extracted 24 weeks after ovario-hysterectomy and were scanned by micro-computed tomography. The evaluation parameters were bone mineral density (BMD), trabecular bone volume (BV/TV), trabecular number (Tb.N), trabecular thickness, and trabecular separation (Tb.Sp). The tibial samples were evaluated after hematoxylin and eosin and Masson's trichrome staining. The sham group had significantly higher BMD, BV/TV, and Tb.N values and the lowest Tb.Sp value compared to the ovario-hysterectomy group. The histological analyses revealed a loss of the bony trabeculae and an increase in osteoporotic changes in the bone of the ovario-hysterectomy-induced osteoporosis group compared to the control group. Our results indicate that an ovario-hysterectomy-induced rabbit model would be a safe, reproducible model for postmenopausal osteoporosis studies.