CHARACTERIZATION OF CHOLECYSTOKININ OCTAPEPTIDE-STIMULATED ENDOGENOUS DOPAMINE RELEASE FROM RAT NUCLEUS ACCUMBENS INVITRO

1. The effect of cholecystokinin sulphated octapeptide (CCK8S) on endogenous dopamine release was examined in rat striatal and nucleus accumbens slices, by high performance liquid chromatography (h.p.l.c) with electrochemical detection. 2. CCK8S was shown to increase dopamine release from slices of nucleus accumbens but not striatum in a dose-dependent manner between 0.1 and 10 μM. 3. Pentagastrin was without effect on dopamine release at doses up to 10 μM. 4. The dopamine release produced in the presence of CCK8S was abolished by preincubation of the slice with 1.0 or 10.0 nM L-364,718 (the CCK(A)-selective antagonist) while 1 μM L-365,260 (the CCK(B)-selective antagonist) had no action. 5. These results suggest that the CCK8S-evoked release of dopamine from the nucleus accumbens is mediated by a CCK(A)-receptor.