title: Chronic imipramine treatment upregulates IR2-imidazoline receptive sites in rat brain.
abstract: A low density of brain IR2-imidazoline receptive sites has previously been linked to depression. In this study we evaluated brain IR2-binding sites in a rat model of depression, olfactory bulbectomy, and determined the effects of chronic imipramine treatment in vivo on these sites. Compared with sham-operated controls, adaptation to olfactory bulbectomy had no effect on either the density (Bmax) or affinity (KD) of [3H]-idazoxan binding to brain IR2 sites. However, 25 days of imipramine treatment (i.p., 20 mg/kg/day) enhanced significantly the density of IR2 binding sites, with no change in affinity in both the model and the control group. These results indicate that the brain IR2-imidazoline receptive sites might be a target for antidepressants.
authors.affiliation: Department of Psychiatry, University of Mississippi Medical Center, Jackson 39216-4505, USA.
authors.forename: H
authors.initials: H
authors.lastname: Zhu
authors.forename: I A
authors.initials: IA
authors.lastname: Paul
authors.forename: M
authors.initials: M
authors.lastname: McNamara
authors.forename: A
authors.initials: A
authors.lastname: Redmond
authors.forename: G
authors.initials: G
authors.lastname: Nowak
authors.forename: J E
authors.initials: JE
authors.lastname: Piletz
mesh_terms: D000818:Animals; D000928:Antidepressive Agents; D001921:Brain / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D003863:Depression / Q000378:metabolism; D019329:Idazoxan / Q000378:metabolism; D054755:Imidazoline Receptors; D007099:Imipramine / Q000494:pharmacology*; D008297:Male; D009830:Olfactory Bulb / Q000502:physiology / Q000601:surgery; D051381:Rats; D017207:Rats, Sprague-Dawley; D011955:Receptors, Drug / Q000187:drug effects* / Q000378:metabolism*; D014316:Tritium; D015854:Up-Regulation
chemical_list: D000928:Antidepressive Agents; D054755:Imidazoline Receptors; D011955:Receptors, Drug; D014316:Tritium; D007099:Imipramine; D019329:Idazoxan