The Methylenetetrahydrofolate Reductase 677C→T Polymorphism and Dietary Folate Restriction Affect Plasma One-Carbon Metabolites and Red Blood Cell Folate Concentrations and Distribution in Women

T polymorphism interact to affect methionine-cycle metabolite concentrations is uncertain. We evaluated the effects of dietary folate restriction on relations among folate status indices and plasma concentrations of methionine cycle metabolites in women with the MTHFR 677 C/C and T/T genotypes. Healthy, normohomocysteinemic women (n = 18; 20-30 y old) of adequate B vitamin status, and equally divided according to MTHFR 677C-->T genotype (9 C/C and 9 T/T) were recruited. Folate status indices and methionine cycle metabolites were measured in blood samples collected at baseline and after 7 wk of dietary folate restriction (115 microg dietary folate equivalents/d). Significant negative correlations between plasma total homocysteine concentrations and total or 5-methyl folate concentrations (P = 0.041 and 0.023, respectively) in RBCs were found only in T/T subjects. Formylated folates were detected in RBCs of T/T subjects only, and their abundance was predictive of plasma total homocysteine concentration despite no significant alteration by folate restriction. Plasma concentrations of S-adenosylmethionine and S-adenosylhomocysteine were not significantly affected by dietary folate restriction and the MTHFR 677 T/T genotype. In conclusion, plasma total homocysteine concentrations in subjects with the MTHFR 677 T/T genotype were inversely related to 5-methyl folate concentrations and directly related to formylated folate concentrations in RBCs, even though the latter were not significantly affected by moderate folate restriction. -->
ISSN: 0022-3166
DOI: 10.1093/jn/135.5.1040
Přístupová URL adresa: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::95696db6b62dd1125108cbf810da6f36
https://doi.org/10.1093/jn/135.5.1040
Rights: OPEN
Přírůstkové číslo: edsair.doi.dedup.....95696db6b62dd1125108cbf810da6f36
Autor: David R. Maneval, Bonnie S. Coats, Jesse F. Gregory, Karla P. Shelnutt, Haifa Ghandour, Antonieta Capdevila, Lynn B. Bailey, Peter W. Stacpoole, Jacob Selhub, Eoin P. Quinlivan, Jonathan J. Shuster, Steven R. Davis, Conrad Wagner
Rok vydání: 2005
Předmět:
Zdroj: The Journal of Nutrition. 135:1040-1044
ISSN: 0022-3166
DOI: 10.1093/jn/135.5.1040
Popis: Whether folate status and the methylenetetrahydrofolate reductase (MTHFR) 677C-->T polymorphism interact to affect methionine-cycle metabolite concentrations is uncertain. We evaluated the effects of dietary folate restriction on relations among folate status indices and plasma concentrations of methionine cycle metabolites in women with the MTHFR 677 C/C and T/T genotypes. Healthy, normohomocysteinemic women (n = 18; 20-30 y old) of adequate B vitamin status, and equally divided according to MTHFR 677C-->T genotype (9 C/C and 9 T/T) were recruited. Folate status indices and methionine cycle metabolites were measured in blood samples collected at baseline and after 7 wk of dietary folate restriction (115 microg dietary folate equivalents/d). Significant negative correlations between plasma total homocysteine concentrations and total or 5-methyl folate concentrations (P = 0.041 and 0.023, respectively) in RBCs were found only in T/T subjects. Formylated folates were detected in RBCs of T/T subjects only, and their abundance was predictive of plasma total homocysteine concentration despite no significant alteration by folate restriction. Plasma concentrations of S-adenosylmethionine and S-adenosylhomocysteine were not significantly affected by dietary folate restriction and the MTHFR 677 T/T genotype. In conclusion, plasma total homocysteine concentrations in subjects with the MTHFR 677 T/T genotype were inversely related to 5-methyl folate concentrations and directly related to formylated folate concentrations in RBCs, even though the latter were not significantly affected by moderate folate restriction.
Databáze: OpenAIRE
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