Adaptation biology and medicine : Current trends

0477759 - FGÚ 2018 RIV IN eng M - Monography Chapter
Szárszoi, Ondrej - Fialová, Martina - Asemu, Girma - Neckář, Jan - Ošťádal, Bohuslav - Kolář, František
Tempol and melatonin blunt antiarrhythmic effect of chronic intermittent hypoxia in rats.
Adaptation biology and medicine : Current trends. Vol. 8. New Delhi: Narosa Publishing House, 2017 - (Kawai, Y.; Hargens, A.; Singal, P.), s. 299-309. ISBN 978-81-8487-567-6
R&D Projects: GA ČR(CZ) GAP303/12/1162
Institutional support: RVO:67985823
Keywords : melatonin * hypoxia * oxidative stress * ischemia * arrythmias
OECD category: Physiology (including cytology)

The aim was to find out whether the antiarrhythmic protection conferred by chronic hypoxia involves reactive oxygen species (ROS). Adult male rats were adapted (24-30 exposures) to intermittent hypobaric hypoxia (IHH, 5000 m, 4 h, 5 day a week). Compared to normoxic rats, IHH significantly attenuated the burst of ROS associated with early reperfusion of isolated hearts following 15-min ischemia. The sensitivity of reperfusion arrhythmias was significantly lower in IHH hearts than in normoxic ones, in particular due to the reduced incidence of ventricular fibrillation. Tempo or melatonin given before ischemia decreased reperfusion arrhythmias in the normoxic group, but completely abolished the antiarrhythmic protection in IHH hearts. However, the effect of IHH still persisted in the hearts treated with melatonin only at reperfusion. These results suggest that IHH decreases cardiac susceptibility to reperfusion-induced ventricular arrhythmias via ROS-dependent mechanism during the ischemic period and limitation of oxidative stress at reflow.
Permanent Link: http://hdl.handle.net/11104/0274015