EFFECTS OF CHRONIC ANTIDEPRESSANT TREATMENT ON DOPAMINE-RELATED [H-3] SCH-23390 AND [H-3] SPIPERONE BINDING IN THE RAT STRIATUM

1. The effects of chronic administration of antidepressants on dopamine-related [H-3]SCH 23390 and [H-3]spiperone binding to rat striatal membranes were assessed. 2. The monamine oxidase inhibitors phenelzine (5 or 10 mg kg-1/day) and tranylcypromine (1 mg kg-1/day) and the tricyclic desipramine (10 mg kg-1/day) were administered for 28 days by constant subcutaneous infusion using Alzet (2MLA) osmotic minipumps. 3. These treatments did not alter K(d) estimates for either [H-3]SCH 23390 or [H-3]spiperone binding sites. The monoamine oxidase inhibitors induced a decrease in the B(max) values for both [H-3]SCH 23990 and [H-3]spiperone binding sites. Desipramine induced a decrease in the B(max) value for [H-3]SCH 23390 binding but had no effect on the B(max) value for [H-3]spiperone binding.