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.

A new approach to studying the autoxidation of adrenaline: possibility of the determination of superoxide dismutase activity and the antioxidant properties of various preparations by polarography

“…Известна кардио-и нейротоксичность продуктов окисления катехоламинов [2,9,[14][15][16][17][22][23][24]. Предполагается, что кардиотоксичность адреналина обусловлена не только адренохромом, но и в большей степени АФК, образующимися в процессе окисления адреналина [14].…”

“…Описанный много лет назад хиноидный путь окисления адреналина в настоящее время активно обсуждается в литературе именно в связи с его способностью генерировать активные формы кислорода (АФК). Интерес к этой теме обусловлен также и тем, что продукты окисления адреналина, белки-хиноны (quinoproteins), глутатионовые конъюганты адреналина и адренохрома (GSH adduct) влияют на редокс состояние клетки и ткани [15][16][17][18]. Их действие обусловлено, вероятно, участием в митохондриальных процессах [18,19], в регуляции NO-зависимой гуанилатциклазы [20] и регуляции функционирования тиреоидных гормонов [21].…”

Adrenaline and Noradrenaline: Partners and Actors in the Same Play"

“…When the enzymes dealing with the catabolism of catecholamines are unable to cope efficiently, their levels rise and catecholamines can undergo oxidation. The oxidation rate is faster under enzymatic or metal catalysis (Heacock, 1959, Bindoli et al, 1992, Foppoli et al, 1997, in the presence of the superoxide anion (O 2 • -) or high pH (West, 1947, Spencer et al, 1995, Costa et al, 2007. Although at physiological pH, the oxidation of catecholamines seems to occur very slowly, it has been found to occur in vivo namely in the septic shock (Macarthur et al, 2000).…”

“…For ADR, at physiological pH, partial deprotonation of the amine group of the side chain leads to an irreversible 1,4-intramolecular cyclization, a reaction that occurs through nucleophilic attack of the nitrogen atom at position 6 of the quinone ring, to form "leucoadrenochrome"; leucoadrenochrome is subsequently oxidized to form adrenochrome (Heacock and Mahon, 1958, Bindoli et al, 1992, Bindoli et al, 1999. This indole is often represented as a zwitterionic structure in aqueous solutions (Heacock and Mahon, 1958, Costa et al, 2007 (Figure 5). In summary, the oxidation of catecholamines occurs through two-stages whereby a total of four electrons is removed and an indole is formed by cyclization (Costa et al, 2011).…”

Use of nitro blue tetrazolium in the reaction of adrenaline autooxidation for the determination of superoxide dismutase activity

“…Один из путей метаболизма адреналина, гормона симпатоадреналовой системы, который происходит по хиноидному пути превращения, известен не только образующимися метаболитами -аминохромами, но и возникающими в этом процессе активными формами кислорода [1][2][3][4][5]. Современное состояние этой проблемы достаточно полно освещено в предыдущем нашем исследовании [6].…”