A method was developed to study the unsupplemented phenylalanine hydroxylase system in rat liver slices. All of the components of the systemtetrahydrobiopterin, dihydropteridine reductase, and the hydroxylase itself-are present under conditions which should be representative of the actual physiological state of the animal. The properties of the system in liver slices have been compared to those...

A 25-year-old woman with mild hyperphenylalaninemia developed disabling depression and panic attacks. The mutations on the phenylalanine hydroxylase gene indicated that she might be responsive to tetrahydrobiopterin therapy. Mutation analyses were performed by the John F. Kennedy Institute in Glostrup, Denmark. The response to tetrahydrobiopterin therapy was impressive at an oral dose of 50 mg ...

The rate of release of deuterons into the body water from 2,3,4,5,6-pentadeutero-L-phenylalanine has been shown to be a valid measure of the activity of the phenylalanine hydroxylase system in vivo. At a dose of 0.5 g/kg, the rate of release of deuterons is linear for 60 to 90 min. Male rats, which had previously been shown to have 22 to 25% more phenylalanine hydroxylase activity in liver extr...

The aim of this study is to investigate the ability to prenatally diagnose phenylketonuria (PKU) by using phenylalanine hydroxylase (PAH) gene mutation analysis combined with short tandem repeat (STR) linkage analysis in 118 fetuses from 112 Chinese families. Genomic DNA was extracted from the peripheral blood from members of 112 families and the exons and exon-intron boundaries of the PAH gene...

Phenylalanine hydroxylase was prepared from human foetal liver and purified 800-fold; it appeared to be essentially pure. The phenylalanine hydroxylase activity of the liver was confined to a single protein of mol.wt. approx. 108000, but omission of a preliminary filtration step resulted in partial conversion into a second enzymically active protein of mol.wt. approx. 250000. Human adult and fu...

A method was developed to study the unsupplemented phenylalanine hydroxylase system in rat liver slices. All of the components of the systemtetrahydrobiopterin, dihydropteridine reductase, and the hydroxylase itself-are present under conditions which should be representative of the actual physiological state of the animal. The properties of the system in liver slices have been compared to those...

A method was developed to study the unsupplemented phenylalanine hydroxylase system in rat liver slices. All of the components of the systemtetrahydrobiopterin, dihydropteridine reductase, and the hydroxylase itself-are present under conditions which should be representative of the actual physiological state of the animal. The properties of the system in liver slices have been compared to those...