Age-related effects of methionine-enriched diet on plasma homocysteine concentration and methylation of hepatic DNA in rats.

In the present study we determined the age-related effect of methionine-enriched diet, a model of hyperhomocysteinemia, on the level of plasma homocysteine and hepatic global DNA methylation in rats. Feeding methionine diet to middle-aged rats for only 14 days resulted in a significant increase in plasma homocysteine level and DNA hypomethylation. In contrast, feeding the methionine-containing diet for 2 weeks to juvenile or post-pubertal animals did not alter the level of plasma homocysteine or hepatic DNA methylation.

[Homocysteine metabolism and its role in pathology].

Results of the study of homocysteine metabolism and its role in physiological and pathological processes are given in this review. The participation of homocysteine in the process of methionine synthesis, transsulfuration, formation of homocysteine thiolacton and their regulation, polymorphism of homocysteine metabolism enzymes, the ways of homocysteine and thiolactone incorporation into protein molecule, sources and forms of homocysteine in the blood plasma, the role of hyperhomocysteinemia in pathogenesis of cardiovascular and other diseases have been considered. Principles of homocysteine determination in the blood plasma are described here.