NEUROPEPTIDE-Y STIMULATES BETA-ENDORPHIN RELEASE IN THE BASAL HYPOTHALAMUS - ROLE OF GONADAL-STEROIDS

Recent pharmacological and morphological studies have raised the likel ihood of a regulatory link beteen the neuropeptide Y (NPY) and beta-en dorphin (beta-END) networks in the hypothalamus. To evaluate this link we have examined the effects of NPY administration on the in vivo rel ease of beta-END by push-pull perfusion of the basal hypothalamus. Res ults showed that centrally injected NPY stimulated the in vivo release of beta-END. This effect was evident only in the absence of testicula r steroids since NPY failed to alter beta-END release in intact rats. These data suggest that the well-documented effects of NPY such as inh ibition of pituitary gonadotropin release in gonadectomized rats and s timulation of feeding may be mediated, in part, by stimulation of beta -END.