title: [3H]2-Nitroimipramine: a selective "slowly-dissociating" probe of the imipramine binding site ("serotonin transporter") in platelets and brain.
abstract: Previous studies have demonstrated a close functional and structural relationship between the "high affinity" binding site for [3H]imipramine and the presynaptic and platelet uptake site(s) for serotonin. Recently we have synthesized several nitro derivatives of imipramine which have a very high affinity for the imipramine binding site and which dissociate very slowly when incubations are performed at 0-4 degrees C. In this report, we describe the characteristics of [3H]2-nitroimipramine binding to platelet and brain membranes. Our results support the relative utility of this ligand for studying the impramine binding site (serotonin transporter) since this analogue has both a higher affinity and specific activity than [3H]imipramine. [3H]2-Nitroimipramine by virtue of its extremely slow dissociation rate should be a valuable tool in subsequent characterization and purification of the serotonin uptake or transport site.
mesh_terms: D000818:Animals; D001665:Binding Sites; D001792:Blood Platelets / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D006801:Humans; D007099:Imipramine / Q000031:analogs & derivatives* / Q000378:metabolism*; D066298:In Vitro Techniques; D007700:Kinetics; D008566:Membranes / Q000378:metabolism; D051381:Rats; D012701:Serotonin / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; C025366:serotonin-binding protein; D012701:Serotonin; C030721:2-nitroimipramine; D007099:Imipramine