Concomitant decrease in [3H]imipramine binding in cat brain and platelets after chronic treatment with imipramine.

Cats were treated chronically with imipramine (7.5 mg/kg i.p. twice daily for 20 days). Maximal [3H]dihydroalprenolol binding was reduced in the cerebral cortex of the treated animals whereas maximal [3H]spiroperidol binding to 5HT2-receptors was unchanged. Maximal [3H]imipramine binding was decreased to a similar extent in both hypothalamus and platelets of the same animals. This parallel decrease in [3H]imipramine binding in brain and platelets is discussed in relation to the lower [3H]imipramine binding found in platelets from untreated depressed patients as compared to those from control volunteers.