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Show COLLEGE OF HEALTH UNDERGRADUATE RESEARCH ABSTRACTS Y-TOCOPHEROL SUPPLEMENTATION ATTENUATES ARTERIAL DYSFUNCTION IN DB/DB MICE Paula Fernandes D'Elia, Elisee Jionang Dapeu, Xin Wan, Elizabeth Johnson, Mackenzie Hawkins, Emmanuella Uzoigwe, Lance Deeter (JD Symons, L Panneerseelan, YY Li, T Jalili) College of Health and Division of Endocrinology, Metabolism, and Diabetes University of Utah y-Tocopherol is a form of vitamin E that functions as a lipophilic antioxidant in vivo. W e showed in normoglycemic adults that supplementation of a y-T-rich mixture of tocopherols ameliorates reductions in brachial artery flow-mediated dilation otherwise induced by postprandial hyperglycemia (Mah et al. J Nutr Biochem, 2013). W e hypothesized that y-T supplementation would attenuate arterial dysfunction induced by chronic hyperglycemia. Db/db mice and wild-type C57BLKS controls (WT) were fed an AIN-93G diet containing 0 or 500 mg/kg y-T for 8 w k (9-12 mice/group). Db/db mice had greater (p<0.05) body mass (BM), plasma glucose and vitamin E, and liver malondialdehyde (MDA) compared to W T animals. y-T supplementation to db/db mice increased plasma y-T 7-fold and reduced hepatic M D A compared to db/ db controls (p<0.05), without affecting alpha (a) -T concentrations. Percent relaxation to acetylcholine in precontracted femoral arteries (~150 p m i.d.) was impaired (p<0.05) in db/db controls compared to W T animals, but the impairment was less severe (p<0.05) in db/db mice provided y-T Arterial responses to sodium nitroprusside were unaffected regardless of diabetes or y-T supplementation. Phosphorylated (p) endothelial nitric oxide synthase (p-eNOS) at serine (S) 1177 to total eNOS was lower (p<0.05) in arteries from db/db controls compared to W T mice. No differences existed in p-eNOS S1177 to total eNOS in vascular tissue from W T mice and db/db mice supplemented with y-T These findings suggest that improvements in y-T status protect against endothelial dysfunction during chronic hyperglycemia, potentially by improving nitric oxide bioavailability by mitigating oxidative stress. Paula Fernandes D'Elia J. Dave Symons |
