title: Expression and distribution of kinin B1 receptor in the rat brain and alterations induced by diabetes in the model of streptozotocin.
abstract: A role for kinin B1 receptors was suggested in the spinal cord and peripheral organs of streptozotocin (STZ)-diabetic rats. The present study aims at determining whether B1 receptors are also induced and over-expressed in the brain of STZ-rats at 2, 7, and 21 days post-treatment. This was addressed by in situ hybridization using the [35S]-UTPalphaS-labeled riboprobe and by in vitro autoradiography with the radioligand [125I]-HPP-des-Arg10-Hoe 140. In control rats, B1 receptor mRNA was found widely distributed in many brain regions. Low mRNA levels were found in thalamus and hypothalamus (7-12 nCi/g) while high mRNA signals were detected in cortical regions and hippocampus (18-29 nCi/g). In diabetic rats, B1 receptor mRNA was markedly increased in hippocampus, temporal/parietal cortices and amygdala at 2 and 7 days (+88 to +150%). Low densities of B1 receptor binding sites were detected in all analyzed regions in control rats (0.18-0.37 fmol/mg tissue). In diabetic rats, B1 receptor binding sites were significantly increased in hippocampus, amygdala, temporal/parietal, and perhinal/piriform cortices (+ 55 to + 165 %) at 7 days only. Results highlight an early but transient and reversible up-regulation of B1 receptors in specific brain regions of STZ-diabetic rats. This may offer the advantage of reducing putative central side effects with B1 receptor antagonists if used for the treatment of diabetic complications in the periphery.
authors.affiliation: Département de Physiologie, Faculté de Médecine, Université de Montréal, C.P. 6128, Succursale Centre-ville, Montréal, Québec, Canada H3C 3J7.
authors.forename: Maria Martha
authors.initials: MM
authors.lastname: Campos
authors.forename: Brice
authors.initials: B
authors.lastname: Ongali
authors.forename: Hudson
authors.initials: H
authors.lastname: De Souza Buck
authors.forename: Joost-Peter
authors.initials: JP
authors.lastname: Schanstra
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Girolami
authors.forename: Jean-Guy
authors.initials: JG
authors.lastname: Chabot
authors.forename: Réjean
authors.initials: R
authors.lastname: Couture
mesh_terms: D000818:Animals; D001345:Autoradiography; D001923:Brain Chemistry / Q000502:physiology*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D007091:Image Processing, Computer-Assisted; D017403:In Situ Hybridization; D008297:Male; D015347:RNA Probes; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D043783:Receptor, Bradykinin B1 / Q000096:biosynthesis / Q000378:metabolism*
chemical_list: D015347:RNA Probes; D012333:RNA, Messenger; D043783:Receptor, Bradykinin B1