[Regulation of (-)-sulpiride-induced increase in evoked dopamine release from striatal slices in rat].
The effects of dopamine (DA) agonist and antagonists on (-)-sulpiride-induced increase in electrically evoked DA release from striatal slices of rats were investigated. (-)-Sulpiride at concentrations of 10 nM to 1 microM in the superfusate caused a dose-dependent increase in electrically evoked DA release from the slices. (+)-Sulpiride had little effect on the evoked DA release up to 1 microM. Apomorphine inhibited the electrically evoked DA release which was antagonized by sulpiride. SCH 23390 and forskolin had no effect on the sulpiride-induced enhancement of evoked DA release. Pretreatment with the irreversible DA receptor antagonist, N-ethoxy-carbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ), caused a significant increase in evoked DA release and prevented the sulpiride-induced increase in evoked DA release. These results indicate that the sulpiride-induced increase in evoked DA release is due to an antagonism of the activation of DA autoreceptors by endogenously released DA.
Yamada
S
S
Institute of Brain Diseases, Kurume University School of Medicine, Japan.
Yokoo
H
H
Nishi
S
S
D000818:Animals; D001058:Apomorphine / Q000037:antagonists & inhibitors; D001552:Benzazepines / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D003342:Corpus Striatum / Q000378:metabolism* / Q000502:physiology; D004298:Dopamine / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005071:Evoked Potentials; D008297:Male; D011804:Quinolines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013469:Sulpiride / Q000494:pharmacology*
D001552:Benzazepines; D011804:Quinolines; D005576:Colforsin; C000470:EEDQ; D013469:Sulpiride; D001058:Apomorphine; D004298:Dopamine