COMPARISON OF THE EFFECTS OF THE INTRAVENOUS AND INTRACEREBRAL ROUTES OF NALOXONE AND DIALLYLNORMORPHINE ADMINISTRATION IN THE MORPHINE-DEPENDENT RHESUS MONKEY

When naloxone was administered to morphine-dependent monkeys by both the intravenous and the intracerebro-ventricular routes, low pre-treatment doses of naloxone resulted in equivalent changes in morphine self-administration regardless of the route of pre-treatment. By contrast, the intravenous and intraventricular administration of diallylnormorphine (DANM), the quaternary derivative of nalorphine, provided a pharmacological differentiation of central and peripheral morphine receptors involved in mediating morphine self-administration. When DANM was administered by intraventricular injection, equivalent changes in morphine self-administration were observed at 1/1000 of the dose given to produce the same effect by the intravenous route.