STUDIES IN METHIONINE METABOLISM. II. FASTING PLASMA METHIONINE LEVELS IN NORMAL AND HEPATOPATHIC INDIVIDUALS IN RESPONSE TO DAILY METHIONINE INGESTION 1

Abstract

The fasting plasma level for L-methionine in normal individuals ranges from 0.25 to 0.48 mg./100 cc. Admn. of 9 g. of DL-methionine daily to such individuals results in elevation of the fasting L-methionine not in excess of 2 mg./100 cc. Admn. of 9 g. of DL-methionine daily to patients with acute and chronic liver disease results in elevation of the plasma fasting L-methionine levels to amts. of more than 2 mg./lOO cc. As the liver damage improves the fasting methionine values return toward normal. Patients with severe liver damage may show values of 30-40 mg./100 cc. under such conditions, and may also show significant elevation of the fasting plasma L-methionine in the absence of any methionine administration. Some individuals who showed marked elevation of plasma methionine levels showed certain toxic manifestations which disappeared when methionine admn. was discontinued, and reappeared when methionine admn. was resumed.