severe hyperphenylalaninemia induced in infant rats by 3 days of treatment with p-chlorophenylalanine ( p-cl phe ) plus phenylalanine ( phe ) did not lower the tryptophan concentration of the brain , and the cerebral serotonin ( 5-ht ) deficiency was attributable entirely to the known suppression to tryptophan hydroxylase ( tph ) by p-cl phe .
C0030135
p-chlorophenylalanine
C0031453
phe