Assessment or central dopaminergic function using plasma-free homovanillic acid after debrisoquin administration

Abstract

Central dopaminergic (DA) function in children and adults was assessed by monitoring plasma-free levels of the dopamine metabolite homovanillic acid (pHVA) before and after a single oral dose and chronic oral administration of debrisoquin. Debrisoquin inhibits peripheral metabolism of dopamine to HVA and does not cross the blood-brain barrier. By reducing peripheral formation of HVA through the use of debrisoquin, the remaining HVA in plasma more accurately reflects central DA activity. Debrisoquin administration resulted in marked reductions of pHVA in each of 12 patients studied. Eleven of the 12 subjects tolerated debrisoquin without physical or behavioral side effects. The debrisoquin administration method appears to be a safe and potentially valid technique for evaluating aspects of central dopaminergic function in children and adults.

Studies of Catecholamine Metabolism in Schizophrenia/Psychosis-I

“…This fact, along with other problems noted next, tends to confound the interpretation of MHPG data that are obtained in pa tients who are receiving DBQ. There seems to be little question that the administration of DBQ results in a decrement of MHPG in plasma, CSF, and urine (Maas et al 1988;Swann et al 1980;Riddle et al 1986), but the degree to which this decrease is of central origin remains open to question. In the report by Maas et al (1979a) it was found that DBQ administration resulted in a decrement of MHPG production by brain.…”