Effect of 5-α-Dihydrotestosterone on Gonadotropin Secretion and Estrous Behavior in the Female Wistar Rat

Abstract

The effect of 5-α-dihydrotestosterone (DHT) on ovarian compensatory hypertrophy (OCH) and estrous behavior were studied in Wistar rats. Unilateral ovariectomy of 5 day cycling rats resulted in significant compensatory hypertrophy of the remaining ovary IS days after the operation. Administration of 50, 200 or 1000 μg DHT propionate daily for 15 days blocked OCH. The degree of blockade was dose dependent. Bilateral implantation of free DHT in the medial hypothalamus inhibited OCH, while unilateral implantation either in the medial hypothalamus or pituitary failed to prevent OCH. Treatment of ovariectomized rats with either 1 or 5 mg DHT propionate daily for 20 days induced weak lordosis behavior in 60% and 40% respectively of the rats treated. Lordosis appeared with a long latency (median: 15 days for both groups). Bilateral implantation of either free DHT or DHT propionate also produced lordosis in 72% and 50% of the ovariectomized rats respectively. The results indicate that DHT can influence the activity of the hypothalamic substrates for gonadotropin secretion and sexual behavior in the rat. (Endocrinology89: 1158, 1971)