Urinary Excretion Studies Following the Administration of Pteroic Acid

Abstract

Summary

1. Pteroic acid was administered to normal adult human males and the urine was assayed for “folic acid” with S. faecalis R and for pteroylglutamic acid with L. easel. On the basis of the relative response of these organisms to pteroic acid and pteroylglutamic acid, the apparent concentration of these compound's in the urine was determined.

2. The oral administration of from 2 to 10 mg of pteroic acid resulted in only a very small amount of urinary pteroic acid.

3. Following the intravenous administration of 2 mg of pteroic acid the microbiological assays of the urine indicated that from 15 to 46% of the compound was excreted as pteroic acid and that only about 1% appeared to be converted to pteroylglutamic acid.

4. The excretion studies indicated that only a small proportion of an administered dose of pteroic acid was converted to pteroylglutamic acid and that pteroic acid is poorly absorbed from the gastrointestinal tract.