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Acute temperature effects on function of the chick embryonic heart
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SYSNO ASEP 0465930 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Acute temperature effects on function of the chick embryonic heart Author(s) Vostárek, František (FGU-C) RID, ORCID, SAI
Svatůňková, Jarmila (FGU-C)
Sedmera, David (FGU-C) RID, ORCID, SAISource Title Acta Physiologica. - : Wiley - ISSN 1748-1708
Roč. 217, č. 4 (2016), s. 276-286Number of pages 11 s. Language eng - English Country US - United States Keywords arrhythmias ; calcium imaging ; chick embryo ; conduction block ; heart development ; optical mapping Subject RIV EA - Cell Biology R&D Projects GAP302/11/1308 GA ČR - Czech Science Foundation (CSF) GA13-12412S GA ČR - Czech Science Foundation (CSF) GA16-02972S GA ČR - Czech Science Foundation (CSF) Institutional support FGU-C - RVO:67985823 UT WOS 000379972300005 EID SCOPUS 84978933172 DOI 10.1111/apha.12691 Annotation We analysed the effects of acute temperature change on the beating rate, conduction properties and calcium transients in the chick embryonic heart invitro and in ovo. MethodsThe effects of temperature change (34, 37 and 40 degrees C) on calcium dynamics in isolated ED4 chick hearts invitro were investigated by high-speed calcium optical imaging. For comparison and validation of invitro measurements, experiments were also performed in ovo using videomicroscopy. Artificial stimulation experiments were performed invitro and inovo to uncover conduction limits of heart segments. ResultsDecrease in temperature from 37 to 34 degrees C invitro led to a 22% drop in heart rate and unchanged amplitude of Ca2+ transients, compared to a 25% heart rate decrease in ovo. Increase in temperature from 37 to 40 degrees C invitro and in ovo led to 20 and 23% increases in heart rate, respectively, and a significant decrease in amplitude of Ca2+ transients (atrium -35%, ventricle -38%). We observed a wide spectrum of arrhythmias invitro, of which the most common was atrioventricular (AV) block (57%). There was variability of AV block locations. Pacing experiments invitro and in ovo suggested that the AV blocks were likely caused by relative tissue hypoxia and not by the tachycardia itself. ConclusionThe pacemaker and AV canal are the most temperature-sensitive segments of the embryonic heart. We suggest that the critical point for conduction is the connection of the ventricular trabecular network to the AV canal. Workplace Institute of Physiology Contact Lucie Trajhanová, lucie.trajhanova@fgu.cas.cz, Tel.: 241 062 400 Year of Publishing 2017
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