Induction and quail liver diamine oxidase (histaminase). Part I: Interference of spermidine synthase on the diamine oxidase activity assay using putrescine as substrate.

Treatment with Aroclor 1254 produces a decrease of diamine oxidase (DAO) activity in quail liver microsomes evaluated on deamination of 14C-putrescine and of histamine. The inhibition observed with the 14C-putrescine assay has peculiar behavior; it increase with the increase of 14C-putrescine concentrations until it produces values of extracted radioactivity which are less than the blanks which do not contain proteins. This effect is reserved by dicyclohexylammonium, an inhibitor of spermidine synthase (SPDS). This paper shows that SPDS rapidly decreases the putrescine concentration during the assay of DAO in tissues, particularly when SPDS is increased by induction with Arocolor.