[Clinical significance of changes in tryptophan metabolism]

The Authors describe the various anomalies of the metabolism of tryptophan that are observed in various diseases. The oxidative pathway is most important of the metabolic pathway of the amino acid; the degredation of tryptophan is particularly influenced by steroid hormones and vitamins' want. The metabolic anomalies are demonstrable both in malignant tumors (mostly in bladder cancer and Hodgkin's disease), both during psychiatric diseases (such as depression and schizophrenia) and in the diseases of connective tissue in addition to congenital errors of the degradation of tryptophan (such as Hartnup's disease, tryptophanuria and 3-hydroxychinureninuria). The metabolic pictures are manifest after amino acid's in the diseases of connective tissue but are independent for clinical seriousness and, in any case, less significant than those observed in other pathological pictures, mostly in Hodgkin's disease. The existence of anomalies of tryptophan's metabolism is certainly shown in many diseases, however the true physiopathogenetic meaning of these metabolic alterations is not yet specified. Particularly it is not definite if these alterations are the cause of diseases, which they appear in, or if they are secondary alterations.