title: Vascular endothelial function is improved by oral glycine treatment in aged rats.
abstract: Glycine has been used to reduce oxidative stress and proinflammatory mediators in some metabolic disorders; however, its effect on the vasculature has been poorly studied. The aim of this work was to explore the effect of glycine on endothelial dysfunction in aged rats. Aortic rings with intact or denuded endothelium were obtained from untreated or glycine-treated male Sprague-Dawley rats at 5 and 15 months of age. Concentration-response curves to phenylephrine (PHE) were obtained from aortic rings incubated with N(G)-nitro-l-arginine methyl ester (l-NAME), superoxide dismutase (SOD), indomethacin, SC-560, and NS-398. Aortic mRNA expression of endothelial nitric oxide synthase (eNOS), NADPH oxidase 4 (NOX-4), cyclooxygenase 1 (COX-1), cyclooxygenase 2 (COX-2), tumour necrosis factor (TNF)-α, and interleukin-1 β was measured by real time RT-PCR. The endothelial modulation of the contraction by PHE was decreased in aortic rings from aged rats. Glycine treatment improved this modulator effect and increased relaxation to acetylcholine. Glycine augmented the sensitivity for PHE in the presence of l-NAME and SOD. It also reduced the contraction by incubation with indomethacin, SC-560, and NS-398. Glycine increased the mRNA expression of eNOS and decreased the expression of COX-2 and TNF-α. Glycine improved the endothelium function in aged rats possibly by enhancing eNOS expression and reducing the role of superoxide anion and contractile prostanoids that increase the nitric oxide bioavailability.
authors.affiliation: Instituto Mexicano del Seguro Social, Unidad de Investigación Médica en Bioquímica, Distrito Federal, México.
authors.forename: Jaime H
authors.initials: JH
authors.lastname: Gómez-Zamudio
authors.forename: Rebeca
authors.initials: R
authors.lastname: García-Macedo
authors.forename: Martha
authors.initials: M
authors.lastname: Lázaro-Suárez
authors.forename: Maximiliano
authors.initials: M
authors.lastname: Ibarra-Barajas
authors.forename: Jesús
authors.initials: J
authors.lastname: Kumate
authors.forename: Miguel
authors.initials: M
authors.lastname: Cruz
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000375:Aging / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D051545:Cyclooxygenase 1 / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D005998:Glycine / Q000494:pharmacology*; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D053583:Interleukin-1beta / Q000378:metabolism; D008297:Male; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases / Q000378:metabolism; D019331:NG-Nitroarginine Methyl Ester / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D009578:Nitrobenzenes / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013449:Sulfonamides / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D053583:Interleukin-1beta; D009578:Nitrobenzenes; D011720:Pyrazoles; C115461:SC 560; D013449:Sulfonamides; D014409:Tumor Necrosis Factor-alpha; D013481:Superoxides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D010656:Phenylephrine; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D013482:Superoxide Dismutase; D000074663:NADPH Oxidase 4; D019255:NADPH Oxidases; C498911:Nox4 protein, rat; D000109:Acetylcholine; D005998:Glycine; D019331:NG-Nitroarginine Methyl Ester; D007213:Indomethacin
keywords: aging; aortic contraction; contraction aortique; dysfonction endothéliale; endothelium dysfunction; glycine; vieillissement