Guanidinosuccinic aciduria in uremia: A possible alternate pathway for urea synthesis

Abstract

Using column chromatography, paper electrophoresis and differential precipitation technics, a method for separation of plasma and urinary guanidinium compounds is described and the results in uremic patients and control subjects with and without kidney disease are compared. The data show diminished urinary excretion and elevated plasma level of guanidinoacetic acid in uremia, accompanied by the appearance of a metabolite, guanidinosuccinic acid, in the urine. The plasma concentration of ammonia and arginine, and the urinary output of arginine, are unaltered in uremic subjects. The clinical or biologic significance of these findings is unknown but it is suggested, primarily by structural analogy, that guanidinosuccinate represents an alternate pathway for the detoxication of ammonia, the stimulus for which is repression of enzyme by the rising plasma concentration of guanidinoacetate.