Abstract
Summary
Data have been presented showing a decrease of norepinephrine and epinephrine in the plasma and of dopamine, norepinephrine, and epinephrine in the urine of phenylketonuric children. These changes were reversed when the patients were treated with a low-phenylalanine diet. Since plasma tyrosine levels remained unchanged, this decrease appears to be caused by inhibition of dopa decarboxylase by the derivatives of phenylalanine. This would provide further in vivo evidence that the pyridoxal-phosphate dependent decarboxylases represent related or identical enzyme systems.
Get full access to this article
View all access options for this article.