Excretion of xanthurenic acid in urine from patients with diabetes mellitus (author's transl)

Abstract

Yahito Kotake1, 2) has shown that rats continuously fed a high fat and high protein diet contracted diabetes and excreted xanthurenic acid (XA). His coworker has taken urine samples from 23 human diabetics and concentrated them. After separating the urine components with solvent on paper chromatography, he identified XA with diazo, by Millon's reaction and by the ferric sulfate test. XA was detected in most diabetic urine, but not in normal urine, which suggests that there is a significant relationship between XA and diabetes. But the existence of diabetics who do not excrete XA in their urine also has been noticed.Thus, we needed to clarify clinically the rate at which usual diabetic patients excrete XA. XA is known to be produced when there is a deficiency of vitamin B6. Therefore when patients excrete XA in their urine, the administration of vitamin B6 may have a therapeutic effect.In cases of mild or middle grade diabetics, only 30-50% of the patients excreted XA in their urine, but if they were loaded with tryptophan the ratio would increase. We believe that there are some diabetics whose tryptophan metabolism is distorted, since their excretion rate of XA in urine is much higher than that of healthy individuals. Whether these diabetic patients have a shortage of vitamin B6 or there is a decrease in the change of vitamin B6 to the active form, pyridoxal phosphate, is discussed.