STUDIES IN METHIONINE AND SULFUR METABOLISM. I. THE FATE OF INTRAVENOUSLY ADMINISTERED METHIONINE, IN NORMAL INDIVIDUALS AND IN PATIENTS WITH LIVER DAMAGE 1, 2

The cardinal role of the liver in protein and amino acid metabolism has been well established. Consequently, studies of amino acid metabolism oc-cupy a natural and fundamental place in an investi-gation of metabolic aberrations in hepatic disease. In 1913, Van Slyke and Meyer (1) demonstrated that certain amino acids when injected intrave-nously are rapidly removed from the circulation in the normal animal. They also demonstrated that a considerable capacity for temporary storage of amino acids existed in certain tissues, notably liver and muscle. Tolerance to various individual amino acids has been studied in connection with hepatic function. Thus Jastrowitz (2) in 1908 re-ported a greater urinary content of glycine in pa-tients with liver damage than in normals following oral ingestion of glycine. A tolerance test to orally administered tyrosine was proposed by Bernhart and Schneider (3) as an aid to the diagnosis of hepatic disease. Similar procedures with single and multiple amino acid preparations have been studied by other investigators (4, 5). The recent development of specific and sensitive microbiologic procedures for the assay of amino acids (6) makes possible the further study of this problem. By virtue of its prominent role in liver physi-ology, in the work here reported methionine was selected for a study of amino acid metabolism in normal and hepatopathic individuals. The pres-ence of sulfur in the molecule confers an additional 1 This work has been performed under a contract be