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Glutathione status is altered in vitamin B‐6 deficient mice
Author(s) -
Dell'Ova Carly A,
Liang HsinYin,
Davis Steven R
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a345-c
Subject(s) - glutathione , pyridoxine , cystine , glutathione disulfide , cysteine , chemistry , pyridoxal , medicine , vitamin , endocrinology , biochemistry , glutathione reductase , biology , phosphate , glutathione peroxidase , enzyme
Pyridoxal 5′‐phosphate is a required coenzyme for production of cysteine via transsulfuration, but it is unclear if the status of cysteine and glutathione depend on vitamin B‐6 status. We used a murine model to determine the extent to which vitamin B‐6 deficiency decreased the concentrations and reducing capacities of cysteine and glutathione pools in the liver. ICR mice were fed diets containing adequate (5.2 mg pyridoxine/kg diet) or deficient (0.1 mg pyridoxine/kg diet) vitamin B‐6 for 6 weeks. Mice fed the deficient diet had 47% less pyridoxamine 5′‐phosphate and 70% less pyridoxal 5′‐phosphate in liver compared to control mice (P < 0.0001). Free cysteine concentration was unchanged, but free cystine increased 3.5 fold (P < 0.05) and the cysteine:cystine ratio was decreased by 50% in deficient mice (P < 0.05). Free glutathione was decreased by 53% (61.5 ± 4.6 vs 29.5 ± 2.0 nmol/mg protein, P < 0.005) in deficient mice, but glutathione disulfide and the reduced:oxidized glutathione ratio were not significantly different between groups. Total glutathione (free + protein disulfides) differed less between groups (20%, P < 0.05), indicating a larger amount of glutathione‐protein mixed disulfides in vitamin B‐6 deficient liver. Combined, these results indicate that vitamin B‐6 deficiency decreases hepatic glutathione concentrations and results in oxidation of intracellular cysteine and glutathione pools in mice.