title: 2.1 GHz electromagnetic field does not change contractility and intracellular Ca2+ transients but decreases β-adrenergic responsiveness through nitric oxide signaling in rat ventricular myocytes.
abstract: OBJECTIVE
  Due to the increasing use of wireless technology in developing countries, particularly mobile phones, the influence of electromagnetic fields (EMF) on biologic systems has become the subject of an intense debate. Therefore, in this study we investigated the effect of 2.1 GHz EMF on contractility and beta-adrenergic (β-AR) responsiveness of ventricular myocytes.
  
  
  METHODS
  Rats were randomized to the following groups: Sham rats (SHAM) and rats exposed to 2.1 GHz EMF for 2 h/day for 10 weeks (EM-10). Sarcomere shortening and Ca(2+) transients were recorded in isolated myocytes loaded with Fura2-AM and electrically stimulated at 1 Hz, while L-type Ca(2+) currents (I(CaL)) were measured using whole-cell patch clamping at 36 ± 1°C. Cardiac nitric oxide (NO) levels were measured in tissue samples using a colorimetric assay kit.
  
  
  RESULTS
  Fractional shortening and amplitude of the matched Ca(2+) transients were not changed in EM-10 rats. Although the isoproterenol-induced (10(-6) M) I(CaL) response was reduced in rats exposed to EMF, basal I(CaL) density in myocytes was similar between the two groups (p < 0.01). Moreover, EMF exposure led to a significant increase in nitric oxide levels in rat heart (p < 0.02).
  
  
  CONCLUSIONS
  Long-term exposure to 2.1 GHz EMF decreases β-AR responsiveness of ventricular myocytes through NO signaling.
authors.affiliation: a Department of Biophysics , Faculty of Medicine, Akdeniz University , Antalya , Turkey.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Olgar
authors.affiliation: a Department of Biophysics , Faculty of Medicine, Akdeniz University , Antalya , Turkey.
authors.forename: Enis
authors.initials: E
authors.lastname: Hidisoglu
authors.affiliation: a Department of Biophysics , Faculty of Medicine, Akdeniz University , Antalya , Turkey.
authors.forename: Murat Cenk
authors.initials: MC
authors.lastname: Celen
authors.affiliation: a Department of Biophysics , Faculty of Medicine, Akdeniz University , Antalya , Turkey.
authors.forename: Bilge Eren
authors.initials: BE
authors.lastname: Yamasan
authors.affiliation: a Department of Biophysics , Faculty of Medicine, Akdeniz University , Antalya , Turkey.
authors.forename: Piraye
authors.initials: P
authors.lastname: Yargicoglu
authors.affiliation: a Department of Biophysics , Faculty of Medicine, Akdeniz University , Antalya , Turkey.
authors.forename: Semir
authors.initials: S
authors.lastname: Ozdemir
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D020746:Calcium Channels, L-Type / Q000378:metabolism; D004574:Electromagnetic Fields / Q000009:adverse effects*; D055724:Electrophysiological Phenomena / Q000187:drug effects / Q000528:radiation effects; D006352:Heart Ventricles / Q000166:cytology*; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects / Q000528:radiation effects; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects*; D009569:Nitric Oxide / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000528:radiation effects*
chemical_list: D020746:Calcium Channels, L-Type; D011943:Receptors, Adrenergic, beta; D009569:Nitric Oxide; D007545:Isoproterenol; D002118:Calcium
keywords: EMF; calcium; contractility; heart; nitric oxide; ventricular myocyte