title: Modulation of retinal blood flow by kinin B₁ receptor in Streptozotocin-diabetic rats.
abstract: The vasoactive kinin B₁ receptor (B₁R) is overexpressed in the retina of diabetic rats in response to hyperglycemia and oxidative stress. The aim of the present study was to determine whether B₁R could contribute to the early retinal blood flow changes occurring in diabetes. Male Wistar rats were rendered diabetic with a single i.p. injection of Streptozotocin (STZ) and studied 4 days or 6 weeks after diabetes induction. The presence of B₁R in the retina was confirmed by Western blot. The impact of oral administration of the B₁R selective antagonist SSR240612 (10mg/kg) was measured on alteration of retinal perfusion in awake diabetic rats by quantitative autoradiography. Data showed that B₁R was upregulated in the STZ-diabetic retina at 4 days and 6 weeks. Retinal blood flow was not altered in 4-day diabetic rats compared with age-matched controls but was significantly decreased following SSR240612 treatment. In 6-week diabetic rats, retinal blood flow was markedly reduced compared to control rats and SSR240612 did not further decrease the blood flow. These results suggest that B₁R is upregulated in STZ-diabetic retina and has a protective compensatory role on retinal microcirculation at 4 days but not at 6 weeks following diabetes induction.
authors.affiliation: École d'optométrie, Université de Montréal, C.P. 6128, Succursale Centre-Ville, Montréal, QC H3C 3J7, Canada.
authors.forename: Mylène
authors.initials: M
authors.lastname: Pouliot
authors.forename: Simon
authors.initials: S
authors.lastname: Hétu
authors.forename: Karim
authors.initials: K
authors.lastname: Lahjouji
authors.forename: Réjean
authors.initials: R
authors.lastname: Couture
authors.forename: Elvire
authors.initials: E
authors.lastname: Vaucher
mesh_terms: D000818:Animals; D001345:Autoradiography; D001783:Blood Flow Velocity; D015153:Blotting, Western; D065169:Bradykinin B1 Receptor Antagonists; D002560:Cerebrovascular Circulation / Q000502:physiology; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism / Q000503:physiopathology*; D003930:Diabetic Retinopathy / Q000378:metabolism / Q000503:physiopathology*; D004149:Dioxoles / Q000494:pharmacology; D005451:Fluorescein Angiography; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D043783:Receptor, Bradykinin B1 / Q000378:metabolism*; D012039:Regional Blood Flow / Q000502:physiology*; D012171:Retinal Vessels / Q000502:physiology*; D013449:Sulfonamides / Q000494:pharmacology; D015854:Up-Regulation
chemical_list: C487113:2-((3-(1,3-benzodioxol-5-yl)-3-(((6-methoxy-2-naphthyl)sulfonyl)amino)propanoyl)amino)-3-(4-((2,6-dimethylpiperidinyl)methyl)phenyl)-N-isopropyl-N-methylpropanamide; D065169:Bradykinin B1 Receptor Antagonists; D004149:Dioxoles; D043783:Receptor, Bradykinin B1; D013449:Sulfonamides