The adrenochrome pathway: the major route for adrenalin catabolism by polymorphonuclear leucocytes

Oxygen radical production by polymorphonuclear leucocytes stimulated the oxidation of adrenalin through the adrenochrome pathway. This was detected either spectrophotometrically at 480 nm or separated by hplc and detected radiochemically. The oxidation was detectable within 5 min and continued for at least 4 h. Over the adrenalin concentration range 0.3 microM to 10 mM more than 80% of the oxidation that occurred was through the adrenochrome pathway, the remainder being through the amine oxidase, catechol methyl transferase pathway. Medium isolated after stimulation of the polymorphonuclear leucocytes was also able to oxidise adrenalin to adrenochrome. The results provide a cellular mechanism for the formation of adrenochrome and the other metabolites on this pathway of adrenalin metabolism, in inflammatory conditions where polymorphonuclear leucocyte infiltration occurs.