Effect of L-carnitine on ketone bodies, redox state and free amino acids in the liver of hyperammonemic mice.

L-Carnitine stimulates urea synthesis in mice given a LD100 of ammonium acetate. Unprotected mice show decreased levels of hepatic ketone bodies and lowered NADH/NAD+ ratio in both cytosol and mitochondria. L-Carnitine enhances markedly the production of beta-hydroxybutyrate and raises the NADH/NAD+ ratio in mitochondria. The alterations induced by ammonium acetate in the free amino acid pool are prevented by L-carnitine. The results shown in this paper indicate that L-carnitine stimulates fatty acid oxidation as well as flux through the Krebs cycle in hyperammonemic mice and that these effects may be responsible for the increase in urea synthesis in these animals.