ABSTRACT
Ovariectomy (OVX) is applicable in experiments in which some effects related to ovarian hormone deciency can be studied. In this procedure, the ablation of both ovaries is performed.
In women, a reduction of the estrogen levels and the loss of the reproductive capacity are observed at the beginning of menopause. This stage in life goes together with numerous changes in the genitourinary and cardiovascular system, as well as in skin, hair, and bones. Estrogen decrease produces an increase of the bone turnover, which means an increase in the resorption and formation of bone tissue. Resorption is faster than formation so that a loss of trabecular bone occurs, causing a subsequent loss of bone strength. The ovariectomized rat is a model applicable to studies concerning trabecular bone loss caused by induced menopause. The characteristics of this model have been completely described,1,2 and it is frequently used as a model for postmenopausal osteoporosis. However, the rat does not develop fractures, the hallmark of osteoporosis. It is applicable mainly to the study of situations in which the bone fragility increases through resorption, but not to those in which bone formation decreases, as happens with immobility.
