title: Colorimetric assay for monoamine oxidase in tissues using peroxidase and 2,2'-azinodi(3-ethylbenzthiazoline-6-sulfonic acid) as chromogen.
abstract: Monoamine oxidase is assayed in tissue by a colorimetric reaction using horse radish peroxidase and 2,2'-azinodi(ethylbenzthiazoline-6-sulfonic acid to measure H2O2 formed during oxidation of amines. The method has a coefficient of variation of approximately 2.5% and provides results comparable with those of radiometric assay. Monoamine oxidase activities in rat liver mitochondria and crude mitochondrial fraction from brain and with tyramine as a substrate were 18.9 +/- 0.4 and 4.61 +/- 0.15 nmol/min/mg of protein, respectively, using this method. Kinetic parameters of liver and brain monoamine oxidase with various substrates and inhibitors appeared to be the same when determined by either colorimetric or radiometric methods.
mesh_terms: D000818:Animals; D001386:Azides; D052160:Benzothiazoles; D001921:Brain / Q000201:enzymology; D002863:Chromogenic Compounds; D003124:Colorimetry; D006861:Hydrogen Peroxide / Q000032:analysis; D007527:Isoenzymes; D008930:Mitochondria, Liver / Q000201:enzymology; D008995:Monoamine Oxidase / Q000032:analysis*; D010084:Oxidation-Reduction; D009195:Peroxidase; D010544:Peroxidases; D051381:Rats; D019810:Sodium Azide; D013379:Substrate Specificity; D013451:Sulfonic Acids
chemical_list: D001386:Azides; D052160:Benzothiazoles; D002863:Chromogenic Compounds; D007527:Isoenzymes; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D019810:Sodium Azide; D006861:Hydrogen Peroxide; D010544:Peroxidases; D009195:Peroxidase; D008995:Monoamine Oxidase