Tyrosine Hydroxylase Inhibitor

**Semantic type:** Chemical Viewed Functionally

**Definition:** Any substance that inhibits tyrosine 3-monooxygenase (tyrosine hydroxylase), an enzyme that catalyzes the conversion of tyrosine to dihydroxyphenylalanine, a precursor to dopamine, norepinephrine, and epinephrine. Inhibition of tyrosine hydroxylase can lead to a depletion of dopamine and norepinephrine in the brain.