Effects of specific opiate agonists on the naloxone-induced release of luteinizing hormone-releasing hormone from the medial basal hypothalamus in vitro

The effects of specific mu, delta and kappa opiate agonists on the in vitro naloxone-induced release of (LHRH) from the rat medial basal hypothalamus were examined. Naloxone produced a consistent calcium-dependent increase in the release of LHRH. The mu receptor agonist sufentanil was highly effective in inhibiting this increase in LHRH release whereas delta and kappa opiate agonists were ineffective. These results indicate that the effects of naloxone on LHRH release are mediated primarily by mu opiate receptors.