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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1983-9-23
pubmed:abstractText
The levels of S-adenosylmethionine (AdoMet) and of S-adenosylhomocysteine (AdoHcy) as well as the ratio of AdoMet/AdoHcy were determined in the liver, lungs, testes and kidneys of weanling male rats fed a commercial chow diet or 5 different amino acid-defined diets for 1-5 weeks. The amino acid-defined diets used were as follows: diet 1, supplemented with methionine, choline, folic acid and vitamin B12; diet 2, deficient in methionine and choline; diet 3, deficient in methionine alone; diet 4, deficient in choline alone; diet 5, deficient in methionine, choline, folic acid and vitamin B12. All methionine-deficient diets were supplemented with an equimolar dose of its metabolic precursor, homocystine. The animals were sacrificed after 1, 3 and 5 weeks of treatment. In animals fed either the chow diet or diet 1, liver was the organ found to contain the highest levels of AdoMet and AdoHcy. Similarly, in animals fed diet 1 or chow, the testes and lungs contained the lowest level of AdoMet, while the lungs contained the lowest levels of AdoHcy. In general, the tissue levels of AdoHcy and AdoMet in rats fed diet 1 were very similar to the corresponding values found in chow-fed rats. Diet 1 feeding, however, led to higher hepatic levels of AdoMet than did the administration of the chow diet. The administration of the methyl-deficient diets generally led to decreased hepatic AdoMet contents at 3 and 5 weeks; the methyl-deficient diets also led to increased AdoHcy contents and decreased AdoMet:AdoHcy ratios when compared with diet 1. Linear regression analysis showed a significant direct correlation between the observed hepatic AdoMet levels and the methyl content of the diet as well as an inverse correlation between hepatic AdoHcy levels and dietary methyl contents. Unlike liver, the lung and testes did not show any decrease in AdoMet content following feeding of the methyl-deficient diets. These tissues did show, however, early significant increases in AdoHcy contents and corresponding decreases in the ratios of AdoMet:AdoHcy. These changes were found to be proportional to the dietary methyl content. The renal contents of AdoMet, AdoHcy and the ratio of AdoMet/AdoHcy were unaffected by any of the diets administered except for diet 5. The administration of diet 5 to rats for 5 weeks led to a significant increase in renal AdoHcy. These results provide evidence indicating that dietary methyl insufficiency may exert its role in carcinogenesis through a decreased availability of AdoMet in vivo.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0143-3334
pubmed:author
pubmed:issnType
Print
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1051-7
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Tissue levels of S-adenosylmethionine and S-adenosylhomocysteine in rats fed methyl-deficient, amino acid-defined diets for one to five weeks.
pubmed:publicationType
Journal Article