Plasma Dopamine-β-Hydroxylase Activity in Hypertension and Various Neuropsychiatric Disorders

Dopamine-β-hydroxylase (DBH), the enzyme responsible for the biosynthesis of noradrenaline from dopamine, was assayed in the blood plasma of 15 new-borns, 14 children between 5 and 15 years, 106 normal adults, 16 cases with hypertension, 52 patients with schizophrenia, 84 patients with manic-depressive disorders, and 16 with Huntington's disease. DBH activity was very low or lacking in new-borns. The plasma DBH activity varied within a wide range in the control population. The hypertension group of patients had significantly higher DBH activity than the control group. Patients with schizophrenia and manic-depressive disorders had similar mean and variation of the DBH activity as normal patients. Patients with Huntington's disease did not have higher plasma DBH than controls.