Detection and Isolation of Formiminoglutamic Acid from Urine in Folic Acid Deficiency in Humans.,

Abstract

A microbiological assay procedure giving presumptive evidence for presence of formininoglutamic acid (FIGLU) was carried out on urine specimens from normal individuals, children with acute leukemia receiving various types of chemotherapy, and a patient with macrocytic anemia pregnancy. The data indicated strongly that FIGLU was being excreted in children with acute leukemia receiving 4-aminofolic acid antagonists and in macrocytic anemia of pregnancy. A highly purified mercury salt of a glutamic acid precursor was isolated from the urine of a patient with leukemia during amethopterin therapy, and on the basis of its chemical and microbiological properties, concluded to be FIGLU. It is postulated that folic acid antagonists induced a folic acid deficiency, resulting in insufficient tetrahydrofolic acid needed for catabolism of FIGLU. Consequently FIGLU accumulated. It is suggested that determination of FIGLU in human urine may be a useful aid in diagnosing folic acid deficiency in man.