ADRENALECTOMY ATTENUATES THE EFFECT OF CHEMICAL CASTRATION ON ENERGY-BALANCE IN RATS

The individual and combined influences of castration and adrenalectomy on energy balance in rats were investigated in a 2 x 2 factorial design. Castration was chemically achieved by treating rats with Buserelin, a gonadotropin-releasing hormone (GnRH) agonist. During the treatment, the rats were weighed every 2 or 3 d, and the total amount of food consumed was determined. At the end of the 14-d treatment period, rats were killed and their carcasses were analyzed for protein, fat and energy content. In the sham-operated groups, body weight gain was greater in Buserelin-treated rats than in saline-infused animals. However, in the adrenalectomized rats, there was no difference in body weight gain between the Buserelin- and saline-infused animals. In sham-operated groups, body protein and body fat gains were significantly larger in Buserelin-than in saline-infused animals. In saline-infused groups, protein gain was greater in adrenalectomized than in sham-operated animals. On the other hand, in the Buserelin-infused rats, there was no difference in the protein gain between the adrenalectomized and sham-operated rats. The adrenalectomized groups of rats ate less and deposited less fat and energy than their respective sham-operated counterparts. In the sham-operated groups, both the intake and the gain of energy were larger in the Buserelin-treated than in saline-infused rats. The present study indicates that adrenalectomy can significantly attenuate the influence of castration on energy gain, providing evidence that adrenals and ovaries can interact in the regulation of energy balance.