[Congenital disorders of tyrosine metabolism and their correction in children with tumors].

The paper deals with the evaluation of quantitative indexes of urine excretion of tyrosine and its metabolites--highly carcinogenic p-hydroxyphenyllactic acid and homogentisic acid--in infants suffering various tumors and their parents. Also, the effect of ascorbic acid (100 mg/kg body weight daily) on tyrosine metabolism was studied. The sick children and their parents showed increased urine excretion of tyrosine and p-hydroxyphenyllactic acid matched by a decrease in that of homogentisic acid. The said changes suggest inhibition of p-hydroxyphenylpyruvate dioxygenase (CE 1.13.11.27). High doses of ascorbic acid were shown to arrest or significantly inhibit the excretion of carcinogenic metabolite of tyrosine in patients with hemoblastoses and nephroblastoma.