Tryptophan metabolites spontaneous” excretion

Fig. 4. Number of patients examined, divided according to the urological disease and number of those showing abnormal levels of tryptophan metabolites spontaneously excreted. Percentage of the abnormally excreting patients is given A = bladder tumors B = extrabladder tumors C = kidney tumors D = urological diseases (non-neoplastic).

As previously mentioned, 3-hydroxyanthranilic acid was found chro-matographically by Musajo et al. (M18) in the urine of tuberculous patients. This was the starting point for an extensive investigation of tryptophan metabolites excreted spontaneously, i.e., by normal subjects or patients with different diseases all fed a normal diet without added tryptophan. 

Spontaneous Excretion of Tryptophan Metabolites in 28 Patients with Hodgkin s Disease... 

As many as 368 urological patients (Table 5) were examined by us with regard to their spontaneous excretion of tryptophan metabolites. Table 5... 

From our investigation it is evident that abnormal excretion of tryptophan metabolites is not a typical feature of bladder tumor subjects, since human beings with neoplastic and nonneoplastic extrabladder urinary diseases have also been found to excrete spontaneously elevated amounts of tryptophan derivatives. It seems that the metabolic abnormality is not restricted to bladder tumors, but is rather more specific for patients with tumors of the upper urinary tracts and of the renal parenchyma. Actually 59% of these patients (Fig. 4) excreted abnormal amounts of kynurenine, 3-hydroxykynurenine, and 3-hydroxyanthranilic acid. 

One of the rare studies of the excretion of tryptophan metabolites, both spontaneous and after load, by patients with hematological disorders, is the work of Altman and Miller (A4). They reported an elevated urinary excretion of anthranilic acid in 9 children with an unusual congenital anemia referred to as erythrogenesis imperfecta (A4). Oral administration of 1.6 g L-tryptophan to one patient led to increased urinary excretion of anthranilic acid as well as other intermediary metabolites of tryptophan. Massive doses of riboflavin per os during 30 days caused no change in the hematological status, but there appeared to be a decrease in the amount of anthranilic acid excreted. 

Bladder Tumor. In addition to the study of the spontaneous excretion of tryptophan metabolites by bladder tumor patients, a comparison was attempted between the excretion of normal subjects and that of a group of 4 bladder cancer patients after a loading dose of 100 mg/kg of L-tryptophan (B8). 

Interrelations among vitamin Be, hemoblastotic diseases, and tryptophan metabolite excretion have been investigated by Anderson (private communication to Professor L. Musajo) in a case of infantile leukemia showing spontaneous excretion of urinary kynurenine and 3-hydroxykynurenine, whose levels were normalized by daily administration of 50 mg pyridoxine. 

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