Pterin metabolism in normal subjects and hyperphenylalaninaemic patients.

The application of high performance liquid chromatography to the estimation of urinary pterins is illustrated by results from normal subjects and from patients with phenylketonuria, dihydropteridine reductase deficiency and biopterin synthetase deficiency. In normal subjects following a phenylalanine load the is a temporary increase in pterin elimination, the pattern being different to that seen in chronic hyperphenylalaninaemia.