Specific high affinity [3H]imipramine binding sites in rat lung are associated with a non-neuronal uptake site for serotonin.
[3H]Imipramine binds to rat lung membranes. The binding is saturable, of high affinity and sodium-dependent. Drug displacement studies indicate that the binding site in rat lung is similar to that already described in the brain cortex. Tricyclic antidepressants inhibited [3H]imipramine binding in the lung in the low nanomolar range and through a competitive interaction. Serotonin and non-tricyclic serotonin uptake blockers inhibited [3H]imipramine binding in lung in a complex manner. Our results support the view that [3H]imipramine binding and the serotonin recognition site of the transporter are related but not identical.
D000818:Animals; D000928:Antidepressive Agents / Q000378:metabolism; D000929:Antidepressive Agents, Tricyclic / Q000378:metabolism; D001667:Binding, Competitive; D002352:Carrier Proteins; D002540:Cerebral Cortex / Q000378:metabolism; D066298:In Vitro Techniques; D008168:Lung / Q000378:metabolism*; D008297:Male; D008566:Membranes / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011955:Receptors, Drug; D017981:Receptors, Neurotransmitter / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism*; D012964:Sodium / Q000502:physiology; D013237:Stereoisomerism
D000928:Antidepressive Agents; D000929:Antidepressive Agents, Tricyclic; D002352:Carrier Proteins; D011955:Receptors, Drug; D017981:Receptors, Neurotransmitter; C027775:imipramine receptor; D012701:Serotonin; D012964:Sodium