Utilization of Methionine by the Adult Rat: I. Distribution of the Alpha-Carbon of DL-Methionine-2-C14 in Tissues, Tissue Fractions, Expired Carbon Dioxide, Blood and Excreta

Abstract

Present knowledge of the metabolism of methionine in the adult rat has been largely derived from experiments which have demonstrated its need for general tissue synthesis and the formation of spe cial compounds. The labile methyl group of methionine is transferred to various acceptors, resulting in the formation of creatine (du Vigneaud et al., '40), an serine2 (Schenck et al., '43), N'-methylnicotinamide (Perlzweig et al., '43; Ellinger, '48), adrenaline (Keller et al., '50), and choline (du Vigneaud and co-workers, '40). Du Vigneaud and his collaborators ('44) demonstrated that methionine sul fur, but not the carbon chain of this amino acid, is used for the synthesis of cystine. Several investigators have reported studies of the distribution in tissues of sulfur from methionine-S35 (Levin et al., '56; Gaitonde and Richter, '55; Maass et al., '49) and of the methyl group fed as methionine-methyl-C14 (Keller et al., '49; Mackenzie et al., '49).