title: High- and low-affinity binding components for [3H]imipramine in rat cerebral cortex.
abstract: The present study demonstrates that [3H]imipramine binds to both high- and low-affinity imipramine binding components on membranes prepared from rat cerebral cortex. Scatchard and computer analyses of saturation experiments using a wide range of [3H]imipramine concentrations (0.5 nM-50 nM) revealed the presence of two binding components. Inhibition experiments in which membranes were incubated with [3H]imipramine and various concentrations of unlabelled imipramine gave shallow inhibition curves with a Hill coefficient of 0.60 +/- 0.04. When dissociation rates of imipramine were studied, biphasic dissociation curves were obtained with apparent half-times of dissociation of 2.5 +/- 0.4 min and 18.5 +/- 2.5 min. Thus analysis of saturation, competition, and dissociation experiments indicate that [3H]imipramine binds to low as well as high-affinity binding sites in rat cortex.
authors.forename: P G
authors.initials: PG
authors.lastname: Conway
authors.forename: D J
authors.initials: DJ
authors.lastname: Brunswick
mesh_terms: D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins; D002462:Cell Membrane / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism*; D003891:Desipramine / Q000494:pharmacology; D007099:Imipramine / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011955:Receptors, Drug; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D011955:Receptors, Drug; D017981:Receptors, Neurotransmitter; C027775:imipramine receptor; D007099:Imipramine; D003891:Desipramine