Effects of androgens on dietary self-selection and carcass composition in male rats.

In 3 experiments the aromatizable androgen testosterone propionate (TP, .2 mg/day) increased protein (P) and carbohydrate (C) intake and stimulated body weight gain (BWG) in gonadectomized CD-strain male rats. A higher dose (2.0 mg/day) increased P but not C intake and was less effective in stimulating BWG. Postmortem carcass analyses revealed that the elevated P intake of both TP-treated groups was associated with increased carcass P content. The decreased weight of Ss treated with the high dose of TP was due to a reduction in body fat content. The nonaromatizable androgen 5-α-dihydrotestosterone propionate (DHTP, .2 or 2.0 mg/day) also increased P, (but not C intake) and BWG, but it did not alter carcass composition. Unlike TP, the 2 doses of DHTP were equally effective, but neither dose of DHTP was as effective as the low dose of TP in stimulating P and C intake and BWG. Results suggest that (a) androgens can increase selection of dietary P whether or not they exert significant P anabolic effects; (b) DHTP is not the major metabolite responsible for the increases in P and C intake and in BWG caused by TP; and (c) the decreases in C intake and adiposity in rats treated with the high dose of TP may be mediated by aromatized (estrogenic) metabolites of the androgen. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)