Carnitine deficiency, organic acidemias, and Reye's syndrome.

Relative carnitine deficiency is important in the pathophysiology of several disorders, including Reye's syndrome and organic acidemias. In acute clinical crises, carnitine serves as a "buffer," trapping toxic acyl compounds. Mitochondrial failure develops in carnitine deficiency when there is insufficient tissue carnitine available to buffer toxic acyl-CoA metabolites. Toxic levels of acyl-CoA impair the citrate cycle, gluconeogenesis, the urea cycle, and fatty-acid oxidation. Carnitine replacement therapy is safe and induces excretion of toxic acyl groups in the urine.