Title: Effects of betaine in a murine model of mild cystathionine-beta-synthase deficiency.

Authors: Schwahn, Bernd C; Wendel, Udo; Lussier-Cacan, Suzanne; Mar, Mei-Heng; Zeisel, Steven H; Leclerc, Daniel; Castro, Carmen; Garrow, Timothy A; Rozen, Rima

Published In Metabolism, (2004 May)

Abstract: Cystathionine-beta-synthase (CBS) is required for transsulfuration of homocysteine, an amino acid implicated in vascular disease. We studied homocysteine metabolism in mice with mild hyperhomocysteinemia due to a heterozygous disruption of the Cbs gene. Mice were fed diets supplemented with betaine or dimethylsulfonioacetate (DMSA); betaine and DMSA provide methyl groups for an alternate pathway of homocysteine metabolism, remethylation by betaine:homocysteine methyltransferase (BHMT). On control diets, heterozygous mice had 50% higher plasma homocysteine than did wild-type mice. Betaine and DMSA had similar effects in both genotype groups: liver betaine increased dramatically, while plasma homocysteine decreased by 40% to 50%. With increasing betaine supplementation, homocysteine decreased by 75%. Plasma homocysteine and BHMT activity both showed a strong negative correlation with liver betaine. Homocysteinemia in mice is sensitive to a disruption of Cbs and to methyl donor intake. Because betaine leads to a greater flux through BHMT and lowers homocysteine, betaine supplementation may be beneficial in mild hyperhomocysteinemia.

PubMed ID: 15131763

MeSH Terms: No MeSH terms associated with this publication