Abstract
Recently Axelrod et al. have found that metanephrine and normetanephrine are principal metabolites of epinephrine and norepinephrine (1, 2). Wylie et al. showed that the catechol-O-methyltransferase was very strongly and competitively inhibited by pyrogallol (3-6). On the other hand it has been reported by many researchers that catecholamines are also attacked by monoamine oxidase. The purpose of the present experiments was to study the relationship between activities of these enzymes and changes of the level of endogenous catecholamines. It was of interest to know whether there were any changes in endogenous catecholamine metabolism, and whether the activities of O-methyltransferase and monoamine oxidase altered, after the continuous daily administration of an O-methyltra n sfe rase inhibitor, since these enzymes are related to the regulation of endogenous catecholamine metabolism.
