Concentrations in Serum and Urinary Excretion of Guanidine, 1-Methylguanidine, and 1,1-Dimethylguanidine in Chronic Renal Failure

Abstract

Abstract Guanidine (G), 1-methylguanidine (MG), and 1,1-dimethylguanidine (DMG) have long been implicated as uremic "toxins." A method has been developed for determining G, MG, and DMG in serum and urine. Specimens were chromatographed on carboxylate resin, with use of 1 molar NaOH, and quantitated colorimetrically with a modification of the Voges— Proskauer reaction. The mean values for G and MG in the serum of uremic patients were 0.3 and 0.4 mg per liter, respectively. DMG was not detected. Although the urinary excretion of MG is significantly increased in renal failure, the concentrations of G, MG, and DMG in serum are not markedly increased, and it is therefore unlikely that G, MG, or DMG contribute to the toxic manifestations of the uremic syndrome.