title: Modulation of gamma-glutamyl cycle and glutathione levels in rat mammary gland explants.
abstract: The reduced glutathione levels and the enzymes gamma-glutamyl-transpeptidase, 5-oxoprolinase and gamma-glutamylcysteine synthetase, which participate in the metabolism of glutathione through the gamma-glutamyl cycle, were determined in explants from the lactating mammary gland of the rat. Significant activities of the enzyme were found. Two modulators of this cycle were used. L-2-Oxothiazolidine-4-carboxylate, an alternative substrate of 5-oxoprolinase and an intracellular cysteine delivery system, increased the reduced glutathione levels under the experimental conditions used. The other compound utilized, DL-buthionine-SR-sulphoximine, an inhibitor of gamma-glutamylcysteine synthetase, significantly decreased the glutathione levels. This effect is slowly reversible.
authors.forename: J
authors.initials: J
authors.lastname: Puente
authors.forename: M A
authors.initials: MA
authors.lastname: Devoto
authors.forename: M
authors.initials: M
authors.lastname: Sapag-Hagar
mesh_terms: D000581:Amidohydrolases / Q000378:metabolism*; D000818:Animals; D019328:Buthionine Sulfoximine; D046508:Culture Techniques; D005260:Female; D005721:Glutamate-Cysteine Ligase / Q000032:analysis / Q000378:metabolism*; D005978:Glutathione / Q000032:analysis / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000201:enzymology / Q000378:metabolism*; D008717:Methionine Sulfoximine / Q000031:analogs & derivatives / Q000494:pharmacology; D010453:Peptide Synthases / Q000378:metabolism*; D011752:Pyroglutamate Hydrolase / Q000032:analysis / Q000378:metabolism*; D011761:Pyrrolidonecarboxylic Acid; D051381:Rats; D011919:Rats, Inbred Strains; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines; D005723:gamma-Glutamyltransferase / Q000032:analysis / Q000378:metabolism*
chemical_list: D013844:Thiazoles; D053778:Thiazolidines; D008717:Methionine Sulfoximine; D019328:Buthionine Sulfoximine; D005723:gamma-Glutamyltransferase; D000581:Amidohydrolases; D011752:Pyroglutamate Hydrolase; D010453:Peptide Synthases; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione; D011761:Pyrrolidonecarboxylic Acid; C029536:2-oxothiazolidine-4-carboxylic acid