STEROID FEEDBACK IN THE MALE AND FEMALE JAPANESE QUAIL

Abstract

The relative abilities of male and female quail to release LH [luteinizing hormone] were compared. Birds were either injected i.v. with synthetic luteinizing hormone releasing hormone (LH-RH) or stimulated electrically via an electrode placed in the posterodorsal part of the basal hypothalamus. The female quail is under more sex steroid feedback than the male, and this causes the differences between the sexes in their resting LH levels. This disparity may be due to a difference in the affinity of male and female sex steroids for hypothalamic and pituitary tissues. Whereas, in the normal male, testosterone appears to exercise its negative feedback action on the hypothalamus, estrogenic hormones in the laying female function mainly at the level of the pituitary and perhaps also on the hypothalamus.