Blood, 1970, Vol. 35, No. 1, pp. 86-89.
© 1970 American Society of Hematology, Inc.
Brief Report: Lack of Effect of L-Methionine Ingestion on 14CO2 Excretion from L-Histidine (Imidazole-2-14C) in Folic Acid and Vitamin B12 Deficient Humans
HANNES B. STAHELIN 1,
H. S. WINCHELL 1, and
N. KUSUBOV 1
1 Laboratory, University of California, Berkeley, Calif.
Three human subjects with folic acid and one with vitamin B12 deficiency
failed to show any effect of ingestion of L-methionine (400-800 µg./kg. body
weight) on the production of 14CO2 from parenterally administered high specific activity L-histidine (imidazole-2-14C). It is suggested that the inhibitory
effect of methionine on intestinal absorption and cell membrane transport of
histidine can explain previously published effects of methionine on the oxidation of the imidazole-2 carbon atom of L-histidine and that a direct effect of
methionine on histidine metabolism need not be invoked.
Submitted on February 17, 1969
Accepted on July 22, 1969
