Opposing effects of D-1 and D-2 receptor antagonists on acetylcholine levels in the rat striatum.
In contrast to D-2 or mixed D-1/D-2 receptor antagonists which decrease rat striatal acetylcholine levels, the D-1 receptor antagonist SCH 23390 increased this biochemical parameter (ED50 = 0.04 mg/kg s.c.) suggesting a reduction of acetylcholine turnover. SCH 23390 blocked the ability of haloperidol or sulpiride to diminish striatal acetylcholine levels and potentiated the increase in this biochemical parameter induced by the selective D-2 receptor agonist LY 141865. These findings indicate that blockade of D-1 and D-2 receptors causes opposite actions on striatal cholinergic neurons.
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology; D001552:Benzazepines / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D004873:Ergolines / Q000494:pharmacology; D008297:Male; D019257:Quinpirole; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*
D014150:Antipsychotic Agents; D001552:Benzazepines; D004873:Ergolines; D011954:Receptors, Dopamine; D019257:Quinpirole; D000109:Acetylcholine