Influence of cholecystokinin on central monoaminergic pathways |
| |
Authors: | Erik Widerlöv Peter W. Kalivas Mark H. Lewis Arthur J. Prange George R. Breese |
| |
Affiliation: | 1. Department of Psychiatry and Pharmacology, Biological Sciences Research Center, University of North Carolina, School of Medicine, Chapel Hill, NC 27514, U.S.A.;2. Psychiatric Research Center, University of Uppsala, Ulleråker Hospital, S-750 17 Uppsala, Sweden |
| |
Abstract: | Dopamine (DA) and cholecystokinin octapeptide carboxy-terminal (CCK-8) have been found to coexist in some mesolimbic neurons. The present investigation was undertaken in order to study the biochemical and behavioral interactions between CCK-8 and some central monoaminergic pathways. The action of the sulfated form of CCK-8 (10 micrograms/10 microliter intracerebroventricularly) on DA turnover in nucleus accumbens, olfactory tubercles and corpus striatum of the rat was determined after DA synthesis inhibition with alpha-methyl-p-tyrosine (250 mg/kg i.p.). Also, CCK-8 action (1-30 micrograms intracisternally) on DA synthesis was assessed by measuring accumulation of dihydroxyphenylalanine (DOPA) after DOPA-decarboxylase inhibition with NSD-1015 (m-hydroxybenzylhydrazine, 100 mg/kg i.p.). The contents of DA and its main metabolites, dihydroxyphenylacetic acid and homovanillic acid, together with serotonin and its main metabolite, 5-hydroxyindoleacetic acid (5-HIAA), were measured in different brain areas after direct injection of CCK-8 into the ventral tegmental area (A10) or nucleus accumbens. Further, the effect of CCK-8 on amphetamine-induced locomotion and apomorphine-induced stereotypies was studied along with changes in spontaneous locomotion and rearing after CCK-8 injection into the ventral tegmental area and nucleus accumbens. No consistent statistically significant effects of CCK-8 on biochemical or behavioral assessments on measures of DA function were observed. However, injection of high doses of CCK-8 into the ventral tegmental area significantly decreased levels of 5-HIAA in the nucleus accumbens, olfactory tubercles and striatum. |
| |
Keywords: | behavior dopamine high-performance liquid chromatography (HPLC) interaction metabolites neuropeptides serotonin site injections |
本文献已被 ScienceDirect 等数据库收录! |
|