Intravenous loading with arginine-hydrochloride and ornithine-aspartate in siblings of two families, presenting a familial neurological syndrome associated with cystinuria.

1. Arginine-hydrochloride and ornithine-aspartate solutions have been infused intravenously to children of two families. Three children of the WOL. family are affected with hyperargininemia and hyperammonemia, due to a lack of arginase. They present a secondary cystine-lysinuria. The three WIL. siblings are suffering from muscular hypotonia, dwarfism, incomplete renal tubular acidosis and primary cystinuria. 2. The aim was to verify how and to what extent the artificial rise of one serum amino acid could influence the serum concentrations and the urinary losses of the other amino acids. The results found for the serum have been submitted to a statistical analysis of variance. 3. The variations observed for the amino acids of the urea cycle can be interpreted as being the reflections of known metabolic pathways. 4. Additional remarks are made on a paradox in the lysinemia-lysinuria relation after arginine infusion, with a simultaneous rise of this essential amino acid in serum and urine.