Vascular endothelial function is improved by oral glycine treatment in aged rats.
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.
['Gómez-Zamudio|Jaime H|JH|', 'García-Macedo|Rebeca|R|', 'Lázaro-Suárez|Martha|M|', 'Ibarra-Barajas|Maximiliano|M|', 'Kumate|Jesús|J|', 'Cruz|Miguel|M|']
D000109:Acetylcholine D000375:Aging D000818:Animals D001011:Aorta D051545:Cyclooxygenase 1 D051546:Cyclooxygenase 2 D004730:Endothelium, Vascular D005998:Glycine D006801:Humans D007213:Indomethacin D053583:Interleukin-1beta D008297:Male D000074663:NADPH Oxidase 4 D019255:NADPH Oxidases D019331:NG-Nitroarginine Methyl Ester D009569:Nitric Oxide D052250:Nitric Oxide Synthase Type III D009578:Nitrobenzenes D010656:Phenylephrine D011720:Pyrazoles D051381:Rats D017207:Rats, Sprague-Dawley D013449:Sulfonamides D013482:Superoxide Dismutase D013481:Superoxides D014409:Tumor Necrosis Factor-alpha
glycine aging aortic contraction contraction aortique dysfonction endothéliale endothelium dysfunction vieillissement