Nutrition
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We investigated the effect of supplementation with the dipeptide L-alanyl-L-glutamine (DIP) and a solution containing L-glutamine and L-alanine, both in the free form, on the plasma and tissue concentrations of glutamine, glutamate, and glutathione (GSH) in rats subjected to long-duration exercise. ⋯ Chronic oral administration of DIP and free GLN + ALA before long-duration exercise represents an effective source of glutamine and glutamate, which may increase muscle and liver stores of GSH and improve the redox state of the cell.
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The interaction between vitamin A and iron status has been widely reported; however, the exact mechanism involved in this interaction has not been well characterized. The present study investigated the mechanism involved in tissue iron accumulation and changes in the oxidative status in vitamin A-deficient rats. ⋯ These results suggest that vitamin A maintains iron homeostasis by the modulation of liver hepcidin expression. The increase of lipid peroxidation in vitamin A deficiency seems to be iron dependent, whereas protein oxidation is not.
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Randomized Controlled Trial
Prospective analysis of serum carotenoids, vitamin A, and tocopherols in adults with short bowel syndrome undergoing intestinal rehabilitation.
Carotenoids, vitamin A, and tocopherols serve important roles in many key body functions. However, availability of these compounds may be decreased in patients with short bowel syndrome (SBS) due to decreased oral intake of fruits and vegetables and/or decreased intestinal absorption. Little information is available on serum concentrations of carotenoids, vitamin A, and tocopherols during chronic parenteral nutrition (PN) or during PN weaning. The aim of this study was to prospectively examine serum concentrations of a wide variety of carotenoids, vitamin A, and tocopherols in patients with SBS undergoing an intensive 12-wk intestinal rehabilitation program. ⋯ Patients with SBS are depleted in diet-derived carotenoids despite oral and intravenous multivitamin supplementation and dietary adjustment during intestinal rehabilitation and PN weaning. Reduction of PN lipid infusion may improve serum alpha-tocopherol concentrations.