Plasma Methionine After Oral Administration of DL-Methionine in Human Subjects

Abstract

Methionine was administered to fasting normal male and female individuals and to a few subjects with gastro-intestinal pathology. Two dosage schemes were used, a 5 g. tablet dose or a 3% soln., 1 g./15 kg. body wt. Plasma methionine was then determined at intervals after the amino acid had been given using microbiological methods of assay which detected either the L-isomer only or both D- and L-isomers. The concn. of the D-isomer was then calculated by difference. The results suggested more rapid and more efficient absorption of the amino acid when administered in soln. rather than in tablet form. The rate of disappearance of methionine from the plasma was faster in females. There was no evidence to indicate differences in rates of absorption although the rates of disappearance from the plasma were quite different when the 2 isomers were compared.