The gamma-glutamyl cycle should be considered not as a mechanism for amino acid transport but rather a generator of extracellular signals, gamma-glutamyl amino acids, that are converted intracellularly to 5-oxoproline, which activates uptake and/or metabolism of amino acids (74, 75)
Zahir DUZ (Department of Chemistry, Faculty of Science, Dicle University, Diyarbakir/Turkey) for providing laboratory facilities
Performance of the serum cobalamin assay for diagnosis of cobalamin deficiency
90,91 Moreover, epidemiologic studies of different institutions showed that individuals with regular exercise, healthy diet (including more soluble fiber, colorful fruit, vegetables, green tea, or less intake of added sugars, carbs, trans-fats), limiting alcohol intake, avoiding smoking cigarettes and reduced levels of stress, which indeed increase insulin sensitivity
Excess dietary L-cysteine, but not L-cystine, is lethal for chicks but not for rats or pigs