[The effect of phototherapy on serum uric acid (author's transl)].

20 newborn infants treated wih phototherapy for icterus neonatorum had analyzed their glutathione reductase activity in the erythrocytes, serum uric acid concentration and the urinary content of uric acid, xanthine and hypoxanthine before and after phototherapy. The activity of glutathione reductase is a sensitive indicator for the availability of riboflavine. There was a significant decrease of serum riboflavine and of serum uric acid during light therapy. The decrease of serum uric acid concentration is discussed as effect of direct photodecomposition on one hand and an inhibitory effect of riboflavine deficiency on uric acid formation on the other.