title: Polymorphism of glutathione S-transferase P1 gene affects human vitamin C metabolism.
abstract: There are large inter-individual differences in the metabolism of vitamin C (VC), which is composed of both ascorbic acid (AsA) and dehydroascorbic acid (DAsA). AsA is oxidized to DAsA in a series of xenobiotic reactions. Thus, the effects of polymorphism A313G (Ile105Val) in the gene for glutathione S-transferases P1 (GSTP1), one of the most active xenobiotic enzymes, on human VC metabolism were studied. The variant frequency of GSTP1 among the present subjects (n=210) was AA 71.0%; GA 27.0% and GG 1.9%. At 24 h after administration of 1 mmol of VC to young women (n=17; age, 21.0+/-1.1 y), total VC excretion (46.7+/-18.1mg) by AA homozygotes of GSTP1 was greater (p<0.0069) than that (28.2+/-14.0 mg) by GA heterozygotes. One hour after administration of VC, blood total VC levels were also significantly different (p<0.0036) between the homozygotes and heterozygotes. The effects of other polymorphisms in xenobiotic enzymes on VC metabolism were small.
authors.affiliation: High Technology Center, Kagawa Nutrition University, 3-9-21 Chiyoda, Sakado-city, Saitama-ken 350-0288, Japan.
authors.forename: Shizu
authors.initials: S
authors.lastname: Higasa
authors.forename: Masaru
authors.initials: M
authors.lastname: Tsujimura
authors.forename: Mami
authors.initials: M
authors.lastname: Hiraoka
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nakayama
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Yanagisawa
authors.forename: Sadahiko
authors.initials: S
authors.lastname: Iwamoto
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kagawa
mesh_terms: D000328:Adult; D001205:Ascorbic Acid / Q000378:metabolism*; D005260:Female; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*
chemical_list: D005982:Glutathione Transferase; D001205:Ascorbic Acid