Down-Regulation of Central Serotonin S2 Receptors after Repeated Treatment with Quinupramine in Rats

[摘要] References(29)Cited-By(4)The present studies were undertaken to determine whether the repeated administration of quinupramine caused down- or up-regulation of β-, α2-adrenergic, serotonin S2, imipramine and muscarinic cholinergic receptors, as had been demonstrated for tricyclic and atypical antidepressant drugs. Quinupramine administered at 10 mg/kg (p.o.) twice daily for 10 days caused a down-regulation of serotonin S2 receptors in the frontal cortex of the rat as determined by [3H]-ketanserin binding. However, quinupramine did not alter the binding populations of β-adrenergic, muscarinic cholinergic and α2-adrenergic receptors in the rat brain as determined by the Scatchard analysis of the [3H]-ligand binding data. Differing from quinupramine, imipramine caused down-regulation of β-adrenergic and serotonin S2 receptor bindings, and it caused sight but significant upregulation of muscarinic cholinergic receptor bindings. These results show that the antidepressant activity of quinupramine is associated with the central serotonin system, but not with the β-adrenergic system. Accordingly, quinupramine, chemically one of the typical tricyclic antidepressant drugs, seems to be pharmacologically one of the atypical antidepressant drugs, and it was suggested that the central serotonin system plays an important role in the antidepressant activity of quinupramine.

[学科分类] 药理学