title: Behavioral evidence for the involvement of endogenous opioids in the interaction between cholecystokinin and brain dopamine systems.
abstract: The hyperactivity induced by injection of the dopamine (DA) agonist apomorphine into the nucleus accumbens of rats was dose dependently inhibited by intra-accumbal pretreatment with cholecystokinin (CCK-8) (ED50, 0.34 ng). Local treatment with the opioid antagonist naloxone antagonized this inhibitory action of CCK-8 (ED50, 18 ng), but did not change the blocking effect of haloperidol on the apomorphine-induced hyperactivity. These data show that endogenous opioids are concerned in certain interactions between CCK-8 and DA systems.
mesh_terms: D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D004298:Dopamine / Q000502:physiology*; D004723:Endorphins / Q000502:physiology*; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009270:Naloxone / Q000494:pharmacology*; D009714:Nucleus Accumbens / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012686:Septal Nuclei / Q000502:physiology*; D012844:Sincalide / Q000494:pharmacology*
chemical_list: D004723:Endorphins; D009270:Naloxone; D006220:Haloperidol; D012844:Sincalide; D001058:Apomorphine; D004298:Dopamine