Radiation and Environmental Biophysics

, Volume 38, Issue 3, pp 195–199 | Cite as

Induction of cAMP-dependent protein kinase A activity in human skin fibroblasts and rat osteoblasts by extremely low-frequency electromagnetic fields

  • Sibylle Thumm
  • Monika Löschinger
  • Sibylle Glock
  • Hugo Hämmerle
  • H. Peter Rodemann
Original Paper

Abstract 

Sinusoidal extremely low-frequency electromagnetic fields (ELF-EMF; 7–8 mT, 20 Hz) have already been shown to inhibit proliferation and to accelerate terminal differentiation of human skin fibroblasts in vitro. In order to elucidate the underlying processes of signal transduction, we analysed the activity of cAMP-dependent protein kinase (PKA). EMF exposure for 60 min resulted in an increased PKA activity in human skin fibroblasts (2-fold) and rat embryonic osteoblasts (1.7-fold). Long-term exposure for up to 7 days with a constant 1 h-on/1 h-off EMF exposure rhythm indicated a transient stimulation of PKA activity during the first two exposure rhythms followed by a decrease to the baseline levels of sham-exposed controls. Based on these results, we postulate that a modulation of proliferation and differentiation processes in cells of mesenchymal origin is triggered by an immediate and transient EMF-induced increase in PKA activity.

Key words Protein kinase A Human skin fibroblasts Electromagnetic fields 

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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Sibylle Thumm
    • 1
  • Monika Löschinger
    • 2
  • Sibylle Glock
    • 1
  • Hugo Hämmerle
    • 1
  • H. Peter Rodemann
    • 2
  1. 1.Natural and Medical Sciences Institute Reutlingen, University of Tübingen (NMI), Markwiesenstrasse 55, D-72770 Reutlingen, GermanyDE
  2. 2.Section of Radiobiology and Molecular Environmental Research, University of Tübingen, Röntgenweg 11, D-72076 Tübingen, Germany e-mail: hans-peter.rodemann@uni-tuebingen.de Tel.: +49-7071-2985962, Fax: +49-7071-295900DE

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