Abstract
A modified enzyme method for the simultaneous estimation of urinary formiminoglutamic acid (FIGLU) and urocanic acid after a loading with 15g of L-histidine has been applied to 10 normal subjects and 40 patients with various blood disorders. The 24-hour excretion of the two derivatives in normal subjects was within 30mg for each of them and within 60mg for the combined two derivatives. FIGLU in excess was found in 45% of 40 patients, and urocanic acid in excess, in 40% of 25 patients. All of six patients whose hematopoieses were megaloblastic excreted excessive FIGLU or the combined two derivatives. Out of 12 cases in whom the total amount of histidine derivatives exceeded the normal range of 60mg, 11 cases were in excess of FIGLU, and 10 cases, of urocanic acid excretion; 3 cases excreted only FIGLU in excess, and 3 cases, only urocanic acid in excess. Out of these 12 cases, six cases excreted both FIGLU and urocanic acid in excess, and urocanic acid was the predominant constituent in one patient. These results suggested a wide-spread existence of folic acid deficiency in blood disorders, and simultaneously, supported the value of estimating both the histidine derivatives for detecting folate deficiency in humans.
