Jr.: A further study of the utilization of dietary glycine nitrogen for uric acid synthesis in gout

In an earlier report (1) an experiment was de-scribed in which a test dose of glycine-N15 was fed to a gouty subject and the abundance of N'5 in uric acid as well as in other urinary constituents was measured for several days. It was found that three times as much of the administered N15 could be recovered in urinary uric acid in the gouty subject as in the two normal subjects studied. The gouty subject used in this initial study had been deliberately selected on the basis of his ex-cessive basal urinary uric acid excretion in order to determine whether increased basal urinary ex-cretion of uric acid, which has been found to oc-cur in about 25 per cent of all gouty subjects stud-ied (2), can properly be ascribed to overproduc-tion of uric acid. In the present report are in-cluded similar experiments on three further gouty subjects, one also excreting excessive quantities of uric acid in the urine, the other two excreting amounts within the normal range under the pre-scribed dietary conditions. METHODS AND MATERIALS All subj ects were maintained on a constant low purine, restricted protein diet (Table I) for 5 to 10 days before administration of glycine and thereafter throughout the period of urine collections. Estimations of urinary ex-cretion of uric acid and total nitrogen were made during the preliminary and experimental.periods. Isotopic glycine (N1 = 60.5 atom per cent excess) was fed with breakfast to each subject at a dosage level of 100 mg. per Kg. of body weight. All synthetic, isolation and analytical procedures were conducted precisely as in the earlier experiment. In one subject (A. R.) the mag-nitude and turnover rate of the miscible pool of uric acid were determined (3) following intravenous injec-tion of 100 mg. of uric acid-i, 3-N". 1This work was carried out with the support of a grant-in-aid from the National Institute of Arthritis an