Dopamine release in the nucleus accumbens of freely moving rats determined by on-line dialysis: effects of apomorphine and the neuroleptic-like peptide desenkephalin-gamma-endorphin.
This study examined the effects of apomorphine, sulpiride, desenkephalin-gamma-endorphin (DE gamma E) and a combination of DE gamma E with apomorphine on the release of dopamine (DA) and its main metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the nucleus accumbens of freely moving rats. A fully automated on-line brain dialysis system was used. A small dose of s.c. administered apomorphine induced a decrease in the output of DA and DOPAC. Sulpiride, infused into the nucleus accumbens, induced a 2-fold increase in the output of DA, DOPAC and HVA. DE gamma E hardly modified either the basal release of DA, DOPAC and HVA or the apomorphine-induced attenuation of the release of DA and DOPAC. These results indicate a dissociation between the behavioural effects of DE gamma E and its effect on the release of DA in vivo.
D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology; D001058:Apomorphine / Q000494:pharmacology*; D003201:Computers; D003956:Dialysis / Q000379:methods*; D004298:Dopamine / Q000378:metabolism*; D008297:Male; D009043:Motor Activity; D009714:Nucleus Accumbens / Q000378:metabolism*; D010455:Peptides / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012686:Septal Nuclei / Q000378:metabolism*; D001615:beta-Endorphin / Q000494:pharmacology*
D014150:Antipsychotic Agents; D010455:Peptides; D001615:beta-Endorphin; C033558:des-enkephalin-gamma-endorphin; D001058:Apomorphine; D004298:Dopamine