title: Chronic administration of 2-(2-benzofuranyl)-2-imidazoline (2-BFI) induces region-specific increases in [3H]2-BFI binding to rat central imidazoline I2 sites.
abstract: Chronic administration of I(2) ligands increases the density of central I(2) sites as measured in brain homogenates. Here, we have used autoradiography to examine whether the increase in I(2) site density induced by chronic administration of 2-(2-benzofuranyl)-2-imidazoline (2-BFI) is uniform across brain regions. We dosed rats with 2-BFI 7 mg/kg or with saline vehicle i.p. over 96 days. Compared with vehicle-treated rats, this treatment significantly increased specific [(3)H]2-BFI binding only in the arcuate nucleus and area postrema, by 63% and 67% respectively. There were no significant effects in the pineal gland or interpeduncular nucleus which, like the arcuate nucleus and area postrema, are rich in I(2) sites. These data indicate that chronic administration of 2-BFI selectively alters radioligand binding in two I(2) rich brain ideas, namely the arcuate nucleus and area postrema, suggesting there may be more than one population of I(2) sites in the rat brain.
authors.affiliation: Pharmaceutical Sciences Research Institute, Aston University, Birmingham, B4 7ET, UK. micholas.macinnes@kcl.ac.uk
authors.forename: Nicholas
authors.initials: N
authors.lastname: MacInnes
authors.forename: Sheila L
authors.initials: SL
authors.lastname: Handley
mesh_terms: D000345:Affinity Labels / Q000008:administration & dosage*; D000818:Animals; D001345:Autoradiography / Q000379:methods; D001572:Benzofurans / Q000008:administration & dosage* / Q000378:metabolism; D001667:Binding, Competitive / Q000187:drug effects*; D001921:Brain / Q000033:anatomy & histology / Q000187:drug effects* / Q000378:metabolism; D007093:Imidazoles / Q000008:administration & dosage* / Q000378:metabolism; D054755:Imidazoline Receptors; D008297:Male; D051381:Rats; D011955:Receptors, Drug; D014316:Tritium / Q000378:metabolism
chemical_list: D000345:Affinity Labels; D001572:Benzofurans; D007093:Imidazoles; D054755:Imidazoline Receptors; D011955:Receptors, Drug; D014316:Tritium; C103723:2-(2-benzofuranyl)-2-imidazoline