Effects of vitamin E depletion/repletion on vitamin E status and oxidative stress in healthy volunteers

Winklhofer‐Roob, Brigitte M.; Khoschsorur, G.; Meinitzer, Andreas; Maritschnegg, M; Hiller, D.; Wuga, Sandra; Wonisch, Willibald; Cardinault, Nicolas; Sundl, Isabella; Roob, Johannes M.; Ribalta, Josep; Rock, Erin M.

doi:10.1016/s0261-5614(03)80122-x

Cited by 4 publications

(2 citation statements)

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“…The repetition of such stimuli during training could reduce the antioxidant pool especially if the non-enzymatic antioxidant dietary cannot match their utilization (Sen, 2001). It has been recently described that a-tocopherol and/or b-carotene depletion weakened antioxidant status (Winklhofer-Roob et al, 2003). Thus, these results suggest that our subjects may have insufficient intakes in antioxidant nutrient.…”

Section: Effects Of Maximal Exercise Under Normobaric Hypoxia and Normentioning

confidence: 59%

Effects of exercise and training in hypoxia on antioxidant/pro-oxidant balance

Pialoux¹,

Mounier²,

Ponsot

et al. 2006

Eur J Clin Nutr

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Objective: The aim was to investigate the effects of acute exercise under hypoxic condition and the repetition of such exercise in a 'living low-training high' training on the antioxidant/prooxidant balance. Design: Randomized, repeated measures design. Setting: Faculté de Médecine, Clermont-Ferrand, France. Subjects: Fourteen runners were randomly divided into two groups. A 6-week endurance training protocol integrated two running sessions per week at the second ventilatory threshold into the usual training. Intervention: A 6-week endurance training protocol integrated two running sessions per week at the second ventilatory threshold into the usual training. The first hypoxic group (HG, n ¼ 8) carried out these sessions under hypoxia (3000 m simulated altitude) and the second normoxic group (NG, n ¼ 6) in normoxia. In control period, the runners were submitted to two incremental cycling tests performed in normoxia and under hypoxia (simulated altitude of 3000 m). Plasma levels of advanced oxidation protein products (AOPP), malondialdehydes (MDA) and lipid oxidizability, ferric-reducing antioxidant power (FRAP), lipid-soluble antioxidants (a-tocopherol and b-carotene) normalized for triacyglycerols and cholesterol were measured before and after the two incremental tests and at rest before and after training. Results: No significant changes of MDA and AOPP level were observed after normoxic exercise, whereas hypoxic exercise induced a 56% rise of MDA and a 44% rise of AOPP. Plasma level of MDA and arterial oxygen hemoglobin desaturations after the acute both exercises were highly correlated (r ¼ 0.73). a-Tocopherol normalized for cholesterol and triacyglycerols increased only after hypoxic exercise (10-12%, Po0.01). After training, FRAP resting values (À21%, Po0.05) and a-tocopherol/ triacyglycerols ratio (À24%, Po0.05) were diminished for HG, whereas NG values remained unchanged. Conclusions: Intense exercise and hypoxia exposure may have a cumulative effect on oxidative stress. As a consequence, the repetition of such exercise characterizing the 'living low-training high' model has weakened the antioxidant capacities of the athletes. Sponsorship: International Olympic Committee and the Direction Régionale de la Jeunesse et des Sports de la Région Auvergne.

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Section: Effects Of Maximal Exercise Under Normobaric Hypoxia and Normentioning

confidence: 59%

Effects of exercise and training in hypoxia on antioxidant/pro-oxidant balance

Pialoux¹,

Mounier²,

Ponsot

et al. 2006

Eur J Clin Nutr

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“…The content and distribution of α-tocopherol in tissues is connected with their antioxidant capacity and protection of cells, and their structures (El Demerdasch 2004, Gulec et al 2006. A deficiency of tocopherol can cause a disturbance in organism oxidative balance (Winklhofer-Roob et al 2003), and eventually to the appearance of degenerative diseases symptoms.…”

Section: Discussionmentioning

confidence: 99%

The influence of α-tocopherol supplementation on plasma concentration of this vitamin and insulin in sedentary or physically trained rats

Debski

Gralak²,

Gronowska-Senger³

et al. 2011

Polish Journal of Veterinary Sciences

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Male young growing rats of Wistar strain (n=54) were fed a vitamin E deficient diet for 3 days of adaptation period and then 10 days of experimental period. After adaptation half of the rats ran, once per a day, on a treadmill with a rate of 2.0 m/s for 15 minutes for the following 10 days. Animals were given orally 0, 0.5, 1.0 or 4.0 mg/d/rat of α-tocopherol. The aim of the study was to evaluate the influence of physical training on tocopherol and insulin concentrations in the blood plasma of rats treated with different doses of vitamin E. The concentrations of α-tocopherol (HPLC-UV method used) and insulin (rat insulin specific RIA method used) were estimated in the blood plasma. Lower concentration of vitamin E in physically trained animals was observed, which may suggest increased needs of organisms for antioxidants, as a result of increased free radical production. In trained rats a lower concentration of plasma insulin was also observed. This effect is probably related to improvement in insulin action observed in organisms under physical exercise. The most significant impact on plasma α-tocopherol was due to its supplementation level. The treatment of rats with different doses of α-tocopherol was found to be not related to insulin concentration in plasma. A significant increase in feed conversion factor was noted in vitamin E treated animals. The obtained results suggest that the increased requirement of trained rats for antioxidants might be covered by α-tocopherol supplementation.

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