title: Some problems associated with measuring monoamine oxidase activity in the presence of sodium azide.
abstract: The colourimetric assay of monoamine oxidase activity, as hydrogen peroxide production, normally requires the use of sodium azide to inhibit breakdown of hydrogen peroxide by catalase. Sodium azide was shown to act as an uncompetitive inhibitor of benzylamine deamination with an inhibitor constant of 1.5 mM. Catalase activity of isolated rat liver mitochondria could be eliminated with the irreversible inhibitor of catalase, 3-amino-1,2,4-triazole. The treatment did not affect benzylamine deaminating activity. The catalase-free preparation could be used to assay monoamine oxidase activity colourimetrically, as hydrogen peroxide production, in the absence of sodium azide.
authors.affiliation: School of Pharmacy and Biomedical Sciences, University of Portsmouth, United Kingdom.
authors.forename: C J
authors.initials: CJ
authors.lastname: Barwell
authors.forename: S A
authors.initials: SA
authors.lastname: Ebrahimi
mesh_terms: D000640:Amitrole / Q000494:pharmacology; D000818:Animals; D001386:Azides / Q000494:pharmacology*; D001547:Benzaldehydes / Q000378:metabolism; D001596:Benzylamines / Q000378:metabolism; D002374:Catalase / Q000037:antagonists & inhibitors; D003124:Colorimetry; D003641:Deamination / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000378:metabolism; D008297:Male; D008930:Mitochondria, Liver / Q000201:enzymology; D008995:Monoamine Oxidase / Q000032:analysis*; D051381:Rats; D017208:Rats, Wistar; D019810:Sodium Azide
chemical_list: D001386:Azides; D001547:Benzaldehydes; D001596:Benzylamines; D019810:Sodium Azide; C030796:benzylamine; D006861:Hydrogen Peroxide; D002374:Catalase; D008995:Monoamine Oxidase; C032175:benzaldehyde; D000640:Amitrole