Osteoporosis is an age-related disease manifested by loss of bone density, with postmenopausal women at higher risk of developing the disease. This disease can be modeled by removing the ovaries from female mice or rats, as this mimics the bone loss triggered by estrogen deficiency seen in older women. Biocytogen has established an ovariectomy (OVX) model in both mice and rats, in which bone density and other metrics can be measured to monitor disease onset and the impact of treatment interventions.
OVX Mouse Model Build
OVX Experimental Design. C57 BL/6 mice are subjected to sham surgery or ovariectomy. Body weight is tracked over 6 weeks until the endpoint, at which time the uterus weight is recorded, and the femurs are harvested for CT scanning and histologic examination.
Body weight of C57BL/6 mice over time (top) and at the experimental endpoint (bottom left) demonstrates that ovariectomy results in weight gain, while the uterus weight drops, as expected.
Example of micro-CT scan from mice 6 weeks post ovariectomy compared to sham controls.
Ovariectomy-induced osteoporosis. Quantification of the bone parameters measured by CT scanning of ovariectomized C57BL/6 mice (OVX) compared to sham controls. BV/TV, Bone Volume/Tissue Volume. Conn.D, Connectivity Density. Tb.Th., Traebecular thickness. Tb.Sp., Traebecular spacing. Tb.N., Traebecular Number. Ct. BV, Cortical bone volume. Ct.Th., Cortical bone thickness. Tb.BS/TV, Traebecular bone surface/tissue volume. SMI, structure model index. Values are expressed as mean ± SEM. *** p<0.001, **p<0.01，*p<0.05.
OVX Model Build in Rats
Experimental design. 12-week-old Sprague-Dawley (SD) female rats were subjected to ovariectomy or sham surgery. Serum and Micro-CT analysis were performed over a period of 8 weeks as indicated.
Post-ovariectomy measurements of alkaline phosphatase and bone mineral density indicate bone loss in the OVX rats compared to sham controls. Values are expressed as mean ± SEM. n=8, T-test, * p<0.05, **p<0.01.
OVX-induced changes in bone structure and mineral density in SD rats. 8 weeks after OVX, rats were sacrificed and femurs were collected. Micro-CT was employed to assess bone structure (A) and mineral density (B) analysis. G1, Sham. G2, OVX.
Values represent mean ± SEM. n=5-10, T-test, * p<0.05, **p<0.01.