Serum amino acids were determined in 22 epileptic children treated with valproic acid. This treatment caused hypocarnitinemia in all, and hyperammonemia in 16. Regardless of the blood ammonia levels, values for glutamic acid, arginine, glycine, serine and alanine were higher than those of normal controls, while aspartic acid and ornithine were lower. These findings suggest that valproate causes intramitochondrial dysfunction of the urea cycle.
Key words Valproate - Hyperaminoacidemia - Carnitine - Urca cycle