Effects of dihydrotestosterone administration on the expression of reproductive and body weight regulatory factors in ovariectomized and estradiol-treated female rats.

To clarify the direct effects of androgens, the changes in the hypothalamic levels of reproductive and appetite regulatory factors induced by chronic dihydrotestosterone (DHT) administration were evaluated in female rats. DHT treatment increased the BW and food intake of the ovariectomized rats, but not the estradiol (E2)-treated rats. DHT administration suppressed the expression of a hypothalamic anorexigenic factor. Although the kisspeptin (Kiss1) mRNA levels of the anterior hypothalamic block (the anteroventral periventricular nucleus, AVPV) were increased in the E2-treated rats, DHT administration did not affect the Kiss1 mRNA levels of the AVPV in the ovariectomized or E2-treated rats. Conversely, DHT administration reduced the Kiss1 mRNA levels of the posterior hypothalamic block (the arcuate nucleus, ARC) in the ovariectomized rats. Although the Kiss1 mRNA levels of the posterior hypothalamic block (ARC) were decreased in the E2-treated rats, DHT administration did not affect the Kiss1 mRNA levels of the ARC in these rats. Serum luteinizing hormone levels of these groups exhibited similar patterns to the Kiss1 mRNA levels of the ARC. These results showed that DHT affects the production of hypothalamic reproductive and appetite regulatory factors, and that these effects of DHT differ according to the estrogen milieu.