The labelling of urinary acids after oral doses of deuterated l-phenylalanine and l-tyrosine in normal subjects. quantitative studies with implications for the deuterated phenylalanine load test in phenylketonuria

摘要: Abstract Oral doses of l -[2H5]-phenylalanine (25 mg/kg) and -[2H5]-tyrosine (12.5 were given separately to three normal subjects together a fourth. Blood samples analysed for deuterium labelled phenylalanine tyrosine, urine o- p-hydroxyphenylacetic, p-hydroxyphenyllactic p-hydroxymandelic acids. The labelling patterns the urinary metabolites indicated that para-compounds all originated in both hepatic extra-hepatic tissues. plasma tyrosine did not appear be equilibrium with liver. It is concluded simple quantitative relationship between these synthesis from liver unlikely.