Semicarbazide-sensitive amine oxidase activity in the human heart.
A semicarbazide-sensitive amine oxidase with affinity for benzylamine (Bz.SSAO) was found in the human heart. This enzymatic activity has a K(m) of 278 +/- 35.3 microM and a V(m) of 114.7 +/- 14.7 nmol mg-1 min-1 (mean +/- SE of eight hearts) for benzylamine and is strongly inhibited by 1 mM histamine and by B24, a specific inhibitor of Bz.SSAO. No diamine oxidase activity was found in the human heart. The levels of MAo and B were assayed: MAO A showed a K(m) of 137.1 +/- 16.2 microM and a V(m) of 10.4 +/- 2.5 nmol mg-1 min-1 for serotonin; MAo B had a K(m) of 9.9 +/- 1.6 microM and V(m) of 4.3 +/- 1.1 nmol mg-1 min-1 for beta-phenylethylamine (mean +/- SE of seven hearts). The human heart has high MAO B activity and Bz.SSAO with histaminase activity.
Department of Pharmacology, University of Florence, Italy.
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D000328:Adult; D000375:Aging; D006631:Amine Oxidase (Copper-Containing) / Q000378:metabolism; D000588:Amines / Q000378:metabolism; D001595:Benzylamine Oxidase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001596:Benzylamines / Q000378:metabolism / Q000494:pharmacology; D001667:Binding, Competitive; D009202:Cardiomyopathies; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006632:Histamine / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D008995:Monoamine Oxidase / Q000378:metabolism*; D009206:Myocardium / Q000201:enzymology*; D011700:Putrescine / Q000031:analogs & derivatives / Q000378:metabolism; D011725:Pyridines / Q000494:pharmacology; D012663:Semicarbazides / Q000494:pharmacology*
C094718:3,5-diethoxy-4-aminomethylpyridine; D000588:Amines; D001596:Benzylamines; D004791:Enzyme Inhibitors; D011725:Pyridines; D012663:Semicarbazides; C010059:carbamylhydrazine; C026212:N-acetylputrescine; D006632:Histamine; C030796:benzylamine; D001595:Benzylamine Oxidase; D006631:Amine Oxidase (Copper-Containing); D008995:Monoamine Oxidase; D011700:Putrescine