title: [3H]SCH 23390 binding sites increase after chronic blockade of D-1 dopamine receptors.
abstract: Chronic treatment with SCH 23390, a selective D-1 dopamine receptor antagonist, increased (40%) the density of [3H]SCH 23390 binding sites in striatal membrane preparations but failed to change the apparent KD of the ligand for its binding sites. Haloperidol, which preferentially blocks D-2 receptors, induced only a slight, not significant increase in the total number of [3H]SCH 23390 binding sites. (-)Sulpiride, a selective D-2 receptor blocker, also failed to change either Bmax or KD of [3H]SCH 23390 binding. Thus, chronic blockade of D-1 receptor sites by SCH 23390 can lead to an increase in their total number.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001552:Benzazepines / Q000378:metabolism*; D001665:Binding Sites / Q000187:drug effects; D006220:Haloperidol / Q000494:pharmacology; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008566:Membranes / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000187:drug effects*; D017447:Receptors, Dopamine D1; D013469:Sulpiride / Q000494:pharmacology
chemical_list: D001552:Benzazepines; D011954:Receptors, Dopamine; D017447:Receptors, Dopamine D1; D013469:Sulpiride; D000262:Adenylyl Cyclases; D006220:Haloperidol