Electrophysiologic and cellular characteristics of cardiomyocytes after X-ray irradiation.
The aim of this study was to investigate possible effects of ionizing irradiation on the electrophysiological functionality of cardiac myocytes in vitro. Primary chicken cardiomyocytes with spontaneous beating activity were irradiated with X-rays (dose range of 0.5-7 Gy). Functional alterations of cardiac cell cultures were evaluated up to 7 days after irradiation using microelectrode arrays. As examined endpoints, cell proliferation, apoptosis, reactive oxygen species (ROS) and DNA damage were evaluated. The beat rate of the cardiac networks increased in a dose-dependent manner over one week. The duration of single action potentials was slightly shortened. Additionally, we observed lower numbers of mitotic and S-phase cells at certain time points after irradiation. Also, the number of cells with γH2AX foci increased as a function of the dose. No significant changes in the level of ROS were detected. Induction of apoptosis was generally negligibly low. This is the first report to directly show alterations in cardiac electrophysiology caused by ionizing radiation, which were detectable up to one week after irradiation.
University for Applied Sciences Aschaffenburg, biomems lab, Würzburger Straße 45, 63743 Aschaffenburg, Germany. Electronic address: johannes.friess@h-ab.de.
Johannes L
JL
Frieß
Technische Universität Darmstadt, Developmental Biology and Neurogenetics, Schnittspahnstraße 13, 64287 Darmstadt, Germany.
Anja
A
Heselich
Helmholtz Institute for Heavy Ion Research (GSI), Biophysics Department, Planckstraße 1, 64291 Darmstadt, Germany.
Sylvia
S
Ritter
Technische Universität Darmstadt, Developmental Biology and Neurogenetics, Schnittspahnstraße 13, 64287 Darmstadt, Germany.
Angelina
A
Haber
Technische Universität Darmstadt, Developmental Biology and Neurogenetics, Schnittspahnstraße 13, 64287 Darmstadt, Germany.
Nicole
N
Kaiser
Technische Universität Darmstadt, Developmental Biology and Neurogenetics, Schnittspahnstraße 13, 64287 Darmstadt, Germany.
Paul G
PG
Layer
University for Applied Sciences Aschaffenburg, biomems lab, Würzburger Straße 45, 63743 Aschaffenburg, Germany.
Christiane
C
Thielemann
D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects; D002645:Chickens; D004249:DNA Damage / Q000528:radiation effects; D004260:DNA Repair / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D055724:Electrophysiological Phenomena; D023381:Endpoint Determination; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000528:radiation effects*; D011839:Radiation, Ionizing; D017382:Reactive Oxygen Species / Q000378:metabolism; D014965:X-Rays
D017382:Reactive Oxygen Species
Cardiomyocytes; Electrophysiology; Ionizing radiation; MEA technology; X-rays