title: Monoamine oxidase-induced hydroxyl radical production and cardiomyocyte injury during myocardial ischemia-reperfusion in rats.
abstract: To elucidate the involvement of monoamine oxidase (MAO) in hydroxyl radical production and cardiomyocyte injury during ischemia as well as after reperfusion, we applied microdialysis technique to the heart of anesthetized rats. Dialysate samples were collected during 30 min of induced ischemia followed by 60 min of reperfusion. We monitored dialysate 3,4-dihydrobenzoic acid (3,4-DHBA) concentration as an index of hydroxyl radical production using a trapping agent (4-hydroxybenzoic acid), and dialysate myoglobin concentration as an index of cardiomyocyte injury in the ischemic region. The effect of local administration of a MAO inhibitor, pargyline, was investigated. Dialysate 3,4-DHBA concentration increased from 1.9 ± 0.5 nM at baseline to 3.5 ± 0.7 nM at 20-30 min of occlusion. After reperfusion, dialysate 3,4-DHBA concentration further increased reaching a maximum (4.5 ± 0.3 nM) at 20-30 min after reperfusion, and stabilized thereafter. Pargyline suppressed the averaged increase in dialysate 3,4-DHBA concentration by ∼72% during occlusion and by ∼67% during reperfusion. Dialysate myoglobin concentration increased from 235 ± 60 ng/ml at baseline to 1309 ± 298 ng/ml at 20-30 min after occlusion. After reperfusion, dialysate myoglobin concentration further increased reaching a peak (5833 ± 1017 ng/ml) at 10-20 min after reperfusion, and then declined. Pargyline reduced the averaged dialysate myoglobin concentration by ∼56% during occlusion and by ∼41% during reperfusion. MAO plays a significant role in hydroxyl radical production and cardiomyocyte injury during ischemia as well as after reperfusion.
authors.affiliation: a Department of Cardiac Physiology , National Cerebral and Cardiovascular Center Research Institute , Osaka , Japan ;
authors.forename: Tadakatsu
authors.initials: T
authors.lastname: Inagaki
authors.affiliation: a Department of Cardiac Physiology , National Cerebral and Cardiovascular Center Research Institute , Osaka , Japan ;
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Akiyama
authors.affiliation: a Department of Cardiac Physiology , National Cerebral and Cardiovascular Center Research Institute , Osaka , Japan ;
authors.forename: Cheng-Kun
authors.initials: CK
authors.lastname: Du
authors.affiliation: a Department of Cardiac Physiology , National Cerebral and Cardiovascular Center Research Institute , Osaka , Japan ;
authors.forename: Dong-Yun
authors.initials: DY
authors.lastname: Zhan
authors.affiliation: b Department of Environmental Health , Nara Women's University , Nara , Japan.
authors.forename: Misa
authors.initials: M
authors.lastname: Yoshimoto
authors.affiliation: a Department of Cardiac Physiology , National Cerebral and Cardiovascular Center Research Institute , Osaka , Japan ;
authors.forename: Mikiyasu
authors.initials: M
authors.lastname: Shirai
mesh_terms: D000818:Animals; D003324:Coronary Artery Disease; D017665:Hydroxyl Radical / Q000378:metabolism*; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism*; D017202:Myocardial Ischemia / Q000235:genetics* / Q000378:metabolism*; D015428:Myocardial Reperfusion Injury; D032383:Myocytes, Cardiac; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species
chemical_list: D017382:Reactive Oxygen Species; D017665:Hydroxyl Radical; D008995:Monoamine Oxidase
keywords: 3,4-Dihydroxybenzoic acid; 4-hydroxybenzoic acid; microdialysis; myoglobin; pargyline