Studies on alpha-ketoglutaric aciduria in type I glycogenosis.

Urinary excretion of the organic acids in patients with type I and III glycogenosis was investigated. In all patients with type I glycogenosis, urinary alpha-ketoglutarate concentration ws about 10 times the normal value. alpha-Ketoglutaric aciduria was not improved by the acute or prolonged administration of a large dose of factors for pyruvate- and alpha-ketoglutarate dehydrogenase complex. On the other hand, the level of alpha-ketoglutarate in the urine from type I patients decreased in conjunction with the decrease of plasma lactate and pyruvate concentration after repeated oral glucose loading. Oral citrate loading brought an increased excretion of alpha-ketoglutarate in type I glycogenosis. It is possible that alpha-ketoglutarate dehydrogenase in the rate-limiting step in tricarboxylic acid cycle and in patients with glycogenosis type I, the excessive excretion of alpha-ketoglutarate may be caused by the limited activity of alpha-ketoglutarate dehydrogenase with excessive substrate.