Dopamine-β-hydroxylase and norepinephrine in human cerebrospinal fluid: Effects of monoamine oxidase inhibitors

The effect of the monoamine oxidase inhibitors, clorgyline and pargyline, on central noradrenergic function in depressed patients was assessed by measuring dopamine beta hydroxylase (DBH) and norepinephrine in cerebrospinal fluid (CSF). These drugs caused a significant decrease in DBH in CSF. This decrease is consistent with a reduction in the release of DBH into CSF as noradrenergic firing is slowed by the drugs. Levels of DBH and norepinephrine in CSF were highly correlated. The ratio of CSF norepinephrine to CSF DBH increased when the patients were treated with monoamine oxidase inhibitors, consistent with a drug-induced increase in brain norepinephrine.