Defective remethylation of homocysteine is related to decreased synthesis of coenzymes B2 in thyroidectomized rats.
Amino Acids
; 28(1): 37-43, 2005 Feb.
Article
en En
| MEDLINE
| ID: mdl-15645165
We investigated the influence of hypothyroidism on homocysteine metabolism in rats, focusing on a hypothetical deficient synthesis of FAD by riboflavin kinases. Animals were allocated in control group (n = 7), thyroidectomized rats (n = 6), rats with diet deficient in vitamin B2, B9, B12, choline and methionine (n = 7), thyroidectomized rats with deficient diet (n = 9). Homocysteine was decreased in operated rats (2.6 +/- 1.01 vs. 4.05 +/- 1.0 mumol/L, P = 0.02) and increased in deficient diet rats (29.56 +/- 4.52 vs. 4.05 +/- 1.0 micromol/L, P = 0.001), when compared to control group. Erythrocyte-Glutathione-Reductase-Activation-Coefficient (index of FAD deficiency) was increased in thyroidectomized or deficient diet rats (P = 0.004 for both). Methylenetetrahydrofolate-reductase and methionine-synthase activities were decreased in thyroidectomized rats but not in those subjected to deficient diet. Cystathionine-beta-synthase was increased only in operated rats. Taken together, these results showed a defective re-methylation in surgical hypothyroidism, which was due in part to a defective synthesis of vitamin B2 coenzymes. This defective pathway was overcompensated by the increased Cystathionine-beta-synthase activity.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Riboflavina
/
Enzimas
/
Homocisteína
/
Hipotiroidismo
Tipo de estudio:
Diagnostic_studies
Límite:
Animals
Idioma:
En
Revista:
Amino Acids
Asunto de la revista:
BIOQUIMICA
Año:
2005
Tipo del documento:
Article
País de afiliación:
Francia
Pais de publicación:
Austria