The effects of SCH 23390, YM 09151-2, (+)- and (-)-3-PPP and some classical neuroleptics on D-1 and D-2 receptors in rat neostriatum in vitro.
The actions in vitro of SCH 23390, YM 09151-2 and both enantiomers of 3-PPP on D-1 and D-2 dopamine receptors were investigated in superfused rat neostriatal slices. For comparison the following neuroleptics of different chemical classes were incorporated in our investigations: (+)-bulbocapnine, clozapine, chlorpromazine, cis-flupenthixol, (-)-sulpiride and haloperidol. The increase in the efflux of cyclic AMP was used as a measure for D-1 receptor stimulation. The decrease in the K+-evoked release of [3H]acetylcholine was used as measure of D-2 receptor stimulation. None of the drugs stimulated the D-1 receptor. Only (+)-3-PPP stimulated the D-2 receptor. All other drugs, including (-)-3-PPP, behaved as antagonists on the D-2 receptor, YM 09151-2 being the most potent. SCH 23390 was the most potent antagonist on the D-1 receptor. Haloperidol, cis-flupenthixol and (+)-bulbocapnine showed an appreciable D-1 receptor blocking potency in our model, whereas the other drugs were inactive. We found SCH 23390 to be the most D-1 selective antagonist although the drug still displayed considerable potency on the D-2 receptor. YM 09151-2 was the most D-2 selective antagonist.
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology*; D001060:Aporphines / Q000494:pharmacology; D001549:Benzamides / Q000494:pharmacology*; D001552:Benzazepines / Q000494:pharmacology*; D002421:Caudate Nucleus / Q000187:drug effects* / Q000378:metabolism; D002746:Chlorpromazine / Q000494:pharmacology; D003024:Clozapine / Q000494:pharmacology; D005475:Flupenthixol / Q000494:pharmacology; D006220:Haloperidol / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D010880:Piperidines / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology; D011699:Putamen / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects* / Q000378:metabolism; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2
D014150:Antipsychotic Agents; D001060:Aporphines; D001549:Benzamides; D001552:Benzazepines; D010880:Piperidines; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; C026539:preclamol; D005475:Flupenthixol; D003024:Clozapine; D006220:Haloperidol; D000109:Acetylcholine; C030265:nemonapride; D011188:Potassium; D015056:1-Methyl-3-isobutylxanthine; D002746:Chlorpromazine