Abstract

Simple paper chromatography of urine obtained in the Figlu test has been found satisfactory for determining excess excretion of the imidazole metabolites of histidine. It has been confirmed that examination for these in addition to formiminoglutamic acid is necessary for a full assessment of this test. When excretion of the latter is not abnormal in folic-acid and/or vitamin B₁₂ deficiency, that of urocanic acid, a glycine conjugate of urocanic acid and/or imidazole propionic acid, is usually raised. An abnormally high excretion of hydantoin-5-propionic acid after histidine has also been found in these deficiencies, and its estimation may be of additional use in the evaluation of the Figlu test.