The Excretion of Oxalic Acid in Gouty Patients

Utilizing the very satisfactory HPLC procedure recently reported by Hughes et al. (1), we have determined the urinary excretion of oxalic acid in control subjects (aged 20 to 70 years) and in gouty patients (from 35 to 73 years), before and after allopurinol treatment. The urinary excretion in normal subjects was 27.5±1.89 mg/24h, in gouty patients 31.3±3.08 mg/24h before allopurinol, and 43.22±4.66 mg/24h after treatment. It is evident that there is no substantial difference between normal subjects and gouty patients, while allopurinol significantly increases (p<0.05) the urinary excretion of oxalic acid. Since allopurinol inhibits the incorporation of glycine into purine ribonucleotides, this increase suggests that the glycine might be channeled toward the formation of glyoxylate and oxalic acid in gouty patients (2).Results suggest that the behavior of urinary oxalic acid should be under constant control during allopurinol treatment. (1) Hughes H. et al. (1982) Anal. Biochem. 119, 1-3 (2) Dean D.M. et al. (1968) Clin. Sci. 35, 325-335