Evidence for dopaminomimetic effect of intrastriatally injected cholecystokinin octapeptide in mice.
The behavioural effect of intrastriatally injected cholecystokinin sulphated octapeptide (CCK-8S), and its interactions with the antagonists Z-CCK-(27-32)NH2 and proglumide, were investigated in mice. When injected into the right striatum, CCK-8S (0.05-1 ng) induced contralateral rotations, as did the dopamine agonist apomorphine. Non-sulphated CCK-8 was inactive and sulphated desamino-CCK-7 was only weakly active in this respect. CCK-8S-induced turning was antagonized by co-injected Z-CCK-(27-32)NH2 (0.01-10 ng) or proglumide (0.1-1 micrograms), as well as by intraperitoneal injection of the neuroleptic drug haloperidol. These data suggest that CCK-8S may, in these conditions, stimulate dopamine-mediated neurotransmission, and that Z-CCK-(27-32)NH2, in addition to its peripheral effect, is also a very potent CCK antagonist at the striatal level.
P
P
Worms
J
J
Martinez
C
C
Briet
B
B
Castro
K
K
Biziere
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D003342:Corpus Striatum; D004347:Drug Interactions; D005260:Female; D006220:Haloperidol / Q000494:pharmacology; D007267:Injections; D051379:Mice; D011377:Proglumide / Q000494:pharmacology; D011954:Receptors, Dopamine / Q000187:drug effects*; D012844:Sincalide / Q000008:administration & dosage / Q000494:pharmacology*; D013239:Stereotyped Behavior / Q000187:drug effects
D011954:Receptors, Dopamine; D011377:Proglumide; D006220:Haloperidol; D012844:Sincalide; D001058:Apomorphine