EXCRETION OF 4-AMINO-5-IMIDAZOLECARBOXAMIDE IN HUMAN URINE

Abstract

A simple colorimetric method for the determination of urinary 4-amino-5-imidazolecarboxamide (AIC), a key by-product in purine biosynthesis, has been developed. Data on urine specimens from 69 healthy individuals showed that excretion of this compound averaged 0.98 mg/day. Repeated measurements on the same individuals showed that AIC is roughly comparable to creatinine in the constancy of its excretion. There is a highly significant correlation between AIC and creatinine levels in normal human urine. Only a small portion of ingested AIC was recovered in the urine, a result in accord with previous data from the literature suggesting that AIC readily enters body substrate pools.