The influence of the sulfated cholecystokinin octapeptide (CCK-8S) on the synaptosomal high-affinity [3H]dopamine (DA) uptake was investigated in the medial and lateral part of nucleus accumbens in rats. CCK-8S induced a concentration-dependent biphasic inhibition of [3H]-DA uptake in both subregions. After preincubation of CCK-8S with the synaptosomes the inhibitory effect was completely abolished. Kinetic analysis of the uptake influence suggests an uncompetitive inhibition by CCK-8S; this means that CCK-8S attacks only the DA-uptake carrier complex by inhibitory manner. The possible regulatory relevance of this mechanism is discussed.
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience
- Cell Biology