title: Methylamine metabolism to formaldehyde by vascular semicarbazide-sensitive amine oxidase.
abstract: The capacity of the vascular enzyme, semicarbazide-sensitive amine oxidase (SSAO), to metabolize methylamine to the potentially toxic product, formaldehyde, was tested using rat aortic homogenates and purified porcine aortic SSAO. Formaldehyde production in incubations of enzyme source with methylamine (1 mM) was detected by high performance liquid chromatography and product was confirmed by desorption chemical ionization mass spectrometry (DCI-MS). Inhibitor studies using the specific SSAO inhibitor semicarbazide and the monoamine oxidase inhibitor pargyline indicate that SSAO is responsible for metabolism of methylamine to formaldehyde. These results suggest the possibility that elevated methylamine found in several pathologic states (such as uremia and diabetes mellitus), or generated from exogenous sources, could result in overproduction of formaldehyde in tissues with high SSAO activity, especially blood vessels.
authors.affiliation: Department of Pathology, University of Texas Medical Branch, Galveston.
authors.forename: P J
authors.initials: PJ
authors.lastname: Boor
authors.forename: M B
authors.initials: MB
authors.lastname: Trent
authors.forename: G A
authors.initials: GA
authors.lastname: Lyles
authors.forename: M
authors.initials: M
authors.lastname: Tao
authors.forename: G A
authors.initials: GA
authors.lastname: Ansari
mesh_terms: D006631:Amine Oxidase (Copper-Containing) / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000818:Animals; D002273:Carcinogens / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D005557:Formaldehyde / Q000032:analysis*; D008297:Male; D008744:Methylamines / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D010293:Pargyline / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012663:Semicarbazides / Q000494:pharmacology; D013552:Swine
chemical_list: D002273:Carcinogens; D008744:Methylamines; D012663:Semicarbazides; D005557:Formaldehyde; C010059:carbamylhydrazine; D010293:Pargyline; C027451:methylamine; D006631:Amine Oxidase (Copper-Containing)