. . . . . . . . . . . . "p(MGI:Gpx1) -| a(CHEBI:\"reactive oxygen species\")" . "Approximately 61,000 statements." . "Copyright (c) 2011-2012, Selventa. All rights reserved." . "BEL Framework Large Corpus Document" . . "1.4" . "OBJECTIVE: We tested the hypothesis that deficiency of cellular glutathione peroxidase (GPx-1) enhances susceptibility to endothelial dysfunction in mice with moderate hyperhomocysteinemia. METHODS AND RESULTS: Mice that were wild type (Gpx1+/+), heterozygous (Gpx1+/-), or homozygous (Gpx1-/-) for the mutated Gpx1 allele were fed a control diet or a high-methionine diet for 17 weeks. Plasma total homocysteine was elevated in mice on the high-methionine diet compared with mice on the control diet (23+/-3 versus 6+/-0.3 micromol/L, respectively; P<0.001) and was not influenced by Gpx1 genotype. In mice fed the control diet, maximal relaxation of the aorta in response to the endothelium-dependent dilator acetylcholine (10(-5) mol/L) was similar in Gpx1+/+, Gpx1+/-, and Gpx1-/- mice, but relaxation to lower concentrations of acetylcholine was selectively impaired in Gpx1-/- mice (P<0.05 versus Gpx1+/+ mice). In mice fed the high-methionine diet, relaxation to low and high concentrations of acetylcholine was impaired in Gpx1-/- mice (maximal relaxation 73+/-6% in Gpx1-/- mice versus 90+/-2% in Gpx1+/+ mice, P<0.05). No differences in vasorelaxation to nitroprusside or papaverine were observed between Gpx1+/+ and Gpx1-/- mice fed either diet. Dihydroethidium fluorescence, a marker of superoxide, was elevated in Gpx1-/- mice fed the high-methionine diet (P<0.05 versus Gpx1+/+ mice fed the control diet). CONCLUSIONS: These findings demonstrate that deficiency of GPx-1 exacerbates endothelial dysfunction in hyperhomocysteinemic mice and provides support for the hypothesis that hyperhomocysteinemia contributes to endothelial dysfunction through a peroxide-dependent oxidative mechanism." . . "Selventa" . . . . "2014-07-03T14:30:07.920+02:00"^^ . . .