levels of forebrain serotonin ( 5-ht ) , tryptophan , 5-hydroxyindoleacetic acid ( 5-hiaa ) and hydroxylase cofactor ( bh4 ) were comparable in two experimental mouse strains ( a/j and c57bl/6j ) despite 2-3-fold differences in vitro in the relative activities of forebrain and midbrain tryptophan-5-monooxygenase ( tpoh ; ec 1.14.16.4 ) .
C0020364
hydroxylase
C0041252
tryptophan-5-monooxygenase