TRYPTOPHAN METABOLISM IN CHILDREN WITH RENAL GLYCOSURIA

Abstract

In some patients with renal glycosuria, the lowerings of serum riboflavin and vitamin B_6 values are recognized. Therefore, the present author studied the tryptophan metabolism of children with renal glycosuria. In 30 patients, all of 3 cases with continuous renal glycosuria and 8 out of 27 cases with intermittent renal glycosuria showed abnormal urinary excretion of tryptophan metabolites. These abnormalities were classified in 5 types and it was suggested that the causes of the abnormalities were based on the deficiency of riboflavin or of vitamin B_6 or the lowering of the activities of enzymes, having relations to these vitamins. In the patients with continuous renal glycosuria, these abnormalities became normal by the administration of riboflavin and pyridoxal phosphate, but the glycosuria remained. On the other hand, in the patient with intermittent glycosuria, urinary glucose was disappeared by riboflavin. It is suggested the renal glycosuria has some relations not only with glucose metabolism but also with amino acids metabolism.