Effects of methionine and related compounds on plasma cholesterol level in rats fed a high cholesterol diet.
The comparative effects of methionine and its structurally and metabolically related compounds on plasma cholesterol level were investigated with rats fed a high cholesterol diet. The plasma cholesterol level was significantly enhanced by the dietary addition of methyl compounds such as L-methionine, D-methionine, choline and betaine. On the other hand, the intermediary metabolites of methionine such as homocystine, cysteine and 3-methylthiopropionate reduced plasma cholesterol. S-Methyl-L-cysteine and dimethylglycine had no significant effect. The plasma cholesterol-elevating effects of methionine, betaine and histidine were all prevented, more or less, by the concurrent addition of glycine to the diet, suggesting the existence of a common mechanism for their effects. The results support a possibility that the plasma cholesterol-elevating efficacy of methionine is attributable to its methyl group.
D000818:Animals; D001622:Betaine / Q000494:pharmacology; D002784:Cholesterol / Q000097:blood*; D002791:Cholesterol, Dietary / Q000494:pharmacology*; D005998:Glycine / Q000494:pharmacology; D006128:Growth / Q000187:drug effects; D006639:Histidine / Q000494:pharmacology; D006937:Hypercholesterolemia / Q000139:chemically induced / Q000378:metabolism; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D008715:Methionine / Q000494:pharmacology*; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains
D002791:Cholesterol, Dietary; D001622:Betaine; D006639:Histidine; D002784:Cholesterol; D008715:Methionine; D005998:Glycine