The D1 dopamine receptor antagonist SCH 23390 increases cocaine self-administration in the rat.
Rats trained to intravenously self-administer cocaine hydrochloride on a fixed ratio-5 schedule were subjected to a series of systemic injections of the D1 dopamine receptor selective antagonist SCH 23390 and the D2 dopamine receptor selective antagonist spiperone. SCH 23390 produced a dose-dependent increase in cocaine intake at doses of 5, 10 and 20 micrograms/kg, but the D2 antagonist failed to reliably increase responding except at a dose of 10 micrograms/kg. These results suggest that the D1 antagonist may be more effective at blocking mesolimbic dopamine activity, and that selective D1 receptor activation may be an important component of psychostimulant reward.
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology*; D003042:Cocaine / Q000008:administration & dosage*; D018492:Dopamine Antagonists; D004305:Dose-Response Relationship, Drug; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects* / Q000502:physiology; D017447:Receptors, Dopamine D1; D012646:Self Administration; D013134:Spiperone / Q000494:pharmacology
D001552:Benzazepines; D018492:Dopamine Antagonists; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D013134:Spiperone; D003042:Cocaine