What is 3,4-dihydroxyphenylacetic acid (DOPAC)

One of the key substances, or metabolites, of dopamine produced through the action of monoamine oxidase (MAO). DOPAC is in turn converted to 3-methoxy-4-hydroxyphenylacetic acid (HVA) by COMT, hence comt-inhibItor medications taken to treat Parkinson’s disease cause DOPAC to accumulate, shifting the equilibrium of the DOPA-DOPAC reaction so that DOPA preferentially enters the pathway of conversion into dopamine.