title: Evidence that the gamma-glutamyl cycle functions in vivo using intracellular glutathione: effects of amino acids and selective inhibition of enzymes.
abstract: The function of the gamma-glutamyl cycle was explored in in vivo studies in which amino acids and specific inhibitors of cycle enzymes (gamma-glutamyl transpeptidase, gamma-glutamyl cyclotransferase, gamma-glutamylcysteine synthetase, and 5-oxoprolinase) were administered to mice. The findings, which show that the gamma-glutamyl cycle functions in vivo, support the conclusion that gamma-glutamyl amino acids formed by gamma-glutamyl transpeptidase from externally supplied amino acids and intracellular glutathione are translocated into the cell and thus indicate that there is a significant physiological connection between the metabolism of glutathione and the transport of amino acids.
mesh_terms: D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D005971:Glutamates / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism*; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008715:Methionine / Q000494:pharmacology; D051379:Mice; D012694:Serine / Q000494:pharmacology; D005723:gamma-Glutamyltransferase / Q000378:metabolism
chemical_list: D000596:Amino Acids; D005971:Glutamates; D012694:Serine; D008715:Methionine; D005723:gamma-Glutamyltransferase; D005978:Glutathione