Dopamine-mediated behavior produced by the enkephalin analogue FK 33-824.
Intraperitoneal injection of FK 33-824 produced apomorphine-like stereotyped behavior in rats. Antagonism of this stereotypy by naloxone and neuroleptics suggests that FK 33-824 can activate opiate and dopamine receptors in the brain. Because increased dopaminergic neuronal activity is thought to be involved in schizophrenia and dopamine-mediated stereotypy has been used as an animal model for this illness, these results are consistent with an involvement of endogenous opiate-like peptides in schizophrenia. This involvement provides a possible mechanism for the reported improvement in schizophrenic psychosis produced by naloxone.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D002746:Chlorpromazine / Q000494:pharmacology; D005405:D-Ala(2),MePhe(4),Met(0)-ol-enkephalin; D004298:Dopamine / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004723:Endorphins / Q000494:pharmacology*; D004745:Enkephalins / Q000494:pharmacology*; D006220:Haloperidol / Q000494:pharmacology; D006801:Humans; D008297:Male; D009270:Naloxone / Q000494:pharmacology; D051381:Rats; D011954:Receptors, Dopamine / Q000187:drug effects; D011957:Receptors, Opioid / Q000187:drug effects; D013239:Stereotyped Behavior / Q000187:drug effects*
D004723:Endorphins; D004745:Enkephalins; D011954:Receptors, Dopamine; D011957:Receptors, Opioid; D009270:Naloxone; D005405:D-Ala(2),MePhe(4),Met(0)-ol-enkephalin; D006220:Haloperidol; D001058:Apomorphine; D002746:Chlorpromazine; D004298:Dopamine