title: Oxidation process of adrenaline in freshly isolated rat cardiomyocytes: formation of adrenochrome, quinoproteins, and GSH adduct.
abstract: High concentrations of circulating biogenic catecholamines often exist during the course of several cardiovascular disorders. Additionally, coronary dysfunctions are prominent and frequently related to the ischemic and reperfusion phenomenon (I/R) in the heart, which leads to the release of large amounts of catecholamines, namely adrenaline, and to a sustained generation of reactive oxygen species (ROS). Thus, this work aimed to study the toxicity of adrenaline either alone or in the presence of a system capable of generating ROS [xanthine with xanthine oxidase (X/XO)], in freshly isolated, calcium tolerant cardiomyocytes from adult rats. Studies were performed for 3 h, and cardiomyocyte viability, ATP level, lipid peroxidation, protein carbonylation content, and glutathione status were evaluated, in addition to the formation of adrenaline's oxidation products and quinoproteins. Intracellular GSH levels were time-dependently depleted with no GSSG formation when cardiomyocytes were exposed to adrenaline or to adrenaline with X/XO. Meanwhile, a time-dependent increase in the rate of formation of adrenochrome and quinoproteins was observed. Additionally, as a new outcome, 5-(glutathion- S-yl)adrenaline, an adrenaline adduct of glutathione, was identified and quantified. Noteworthy is the fact that the exposure to adrenaline alone promotes a higher rate of formation of quinoproteins and glutathione adduct, while adrenochrome formation is favored where ROS production is stimulated. This study shows that the redox status of the surrounding environment greatly influences adrenaline's oxidation pathway, which may trigger cellular changes responsible for cardiotoxicity.
authors.affiliation: REQUI MTE (Rede de Química e Tecnologia), Toxicology Department, Faculty of Pharmacy, University of Porto, Porto, Portugal. veramcosta@ff.up.pt
authors.forename: Vera Marisa
authors.initials: VM
authors.lastname: Costa
authors.forename: Renata
authors.initials: R
authors.lastname: Silva
authors.forename: Luísa Maria
authors.initials: LM
authors.lastname: Ferreira
authors.forename: Paula Sério
authors.initials: PS
authors.lastname: Branco
authors.forename: Félix
authors.initials: F
authors.lastname: Carvalho
authors.forename: Maria Lourdes
authors.initials: ML
authors.lastname: Bastos
authors.forename: Rui Albuquerque
authors.initials: RA
authors.lastname: Carvalho
authors.forename: Márcia
authors.initials: M
authors.lastname: Carvalho
authors.forename: Fernando
authors.initials: F
authors.lastname: Remião
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000322:Adrenergic Agonists / Q000494:pharmacology / Q000633:toxicity; D000323:Adrenochrome / Q000378:metabolism*; D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000378:metabolism*; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism*; D007425:Intracellular Membranes / Q000187:drug effects* / Q000378:metabolism; D007700:Kinetics; D032383:Myocytes, Cardiac / Q000378:metabolism*; D010084:Oxidation-Reduction; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism*; D019820:Xanthine / Q000378:metabolism; D014969:Xanthine Oxidase / Q000378:metabolism
chemical_list: D000322:Adrenergic Agonists; D017382:Reactive Oxygen Species; D019820:Xanthine; D000323:Adrenochrome; D000255:Adenosine Triphosphate; D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor); D014969:Xanthine Oxidase; D005978:Glutathione; D002118:Calcium; D004837:Epinephrine