Computer model of the metabolism of phenylalanine in normal subjects and in patients with phenylketonuria

The techniques of systems analysis have been applied to the metabolism of phenylalanine in healthy subjects and in phenylketonuria to derive a computer model. The model consists of seven compartments and four biological functions. Enzyme reactions are assumed to obey Michaelis-Menten kinetics. The computer program is written in FORTRAN. A biological validation of the model has been performed. The computer model has potential value for estimating concentrations of key metabolites in human organs which are not accessible to direct analysis from measurement of metabolites in blood and urine and phenylalanine intake. Such estimates would be helpful in clinical decisions concerning modification or termination of dietary treatment in phenylketonuria.