Neuropeptide Y stimulates beta-endorphin release in the basal hypothalamus: Role of gonadal steroids

Recent pharmacological and morphological studies have raised the likelihood of a regulatory link beteen the neuropeptide Y (NPY) and beta-endorphin (beta-END) networks in the hypothalamus. To evaluate this link we have examined the effects of NPY administration on the in vivo release of beta-END by push-pull perfusion of the basal hypothalamus. Results showed that centrally injected NPY stimulated the in vivo release of beta-END. This effect was evident only in the absence of testicular steroids since NPY failed to alter beta-END release in intact rats. These data suggest that the well-documented effects of NPY such as inhibition of pituitary gonadotropin release in gonadectomized rats and stimulation of feeding may be mediated, in part, by stimulation of beta-END.