It is known from the work of Elwyn et al. (1) that ethanolamine is incorporated as a unit into the choline molecule during the synthesis de novo of this substance. Du Vigneaud et al. (2, 3) showed that at least some of the methyl groups of choline are derived directly from the methyl group of methionine; and in an earlier communication we provided evidence that all the methyl groups originate f...

A consideration of numerous studies in viva indicates that the metabolism of methionine, folic acid, and cyano-B1$ is interrelated. The vitamin has a sparing effect on the methyl group requirement of young chickens, and, conversely, methionine has a sparing effect on the cyano-Blz requirement in chickens and rats (l-4). A more direct demonstration of an impairment in methyl group biosynthesis d...

Intersections in hepatic methyl group metabolism pathways highlights potential competition or compensation of methyl donors. The objective of this experiment was to examine the expression of genes related to methyl group transfer and lipid metabolism in response to increasing concentrations of choline chloride (CC) and DL-methionine (DLM) in primary neonatal hepatocytes that were or were not ex...

Guanidinoacetic acid (GAA) is the natural biosynthetic precursor of creatine, in a metabolic reaction that requires only a methyl group transfer. The use of GAA as a food additive for restoring creatine load in human tissues is rather unexplored and data on efficacy and safety are limited. In particular, an increase in serum homocysteine after GAA administration can be regarded as critical and ...