| First Author | Dayal S | Year | 2002 |
| Journal | Arterioscler Thromb Vasc Biol | Volume | 22 |
| Issue | 12 | Pages | 1996-2002 |
| PubMed ID | 12482825 | Mgi Jnum | J:103367 |
| Mgi Id | MGI:3609289 | Doi | 10.1161/01.atv.0000041629.92741.dc |
| Citation | Dayal S, et al. (2002) Deficiency of glutathione peroxidase-1 sensitizes hyperhomocysteinemic mice to endothelial dysfunction. Arterioscler Thromb Vasc Biol 22(12):1996-2002 |
| abstractText | 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 provide support for the hypothesis that hyperhomocysteinemia contributes to endothelial dysfunction through a peroxide-dependent oxidative mechanism. |
