Biophys J, November 2001, p. 2580-2589, Vol. 81, No. 5

Calcium Protects Differentiating Neuroblastoma Cells during 50 Hz Electromagnetic Radiation

R. Tonini,^* M. D. Baroni,^* E. Masala,^* M. Micheletti, A. Ferroni,^* and M. Mazzanti

 ^*Dipartimento di Fisiologia e Biochimica Generali, I^a Università di Milano, I-20133 Milano;  DIBIT, HSR, I-20100 Milano; and  Dipartimento di Biologia Cellulare e dello Sviluppo, Università "La Sapienza," I-00185 Roma, Italy

Despite growing concern about electromagnetic radiation, the interaction between 50- to 60-Hz fields and biological structures remains obscure. Epidemiological studies have failed to prove a significantly correlation between exposure to radiation fields and particular pathologies. We demonstrate that a 50- to 60-Hz magnetic field interacts with cell differentiation through two opposing mechanisms: it antagonizes the shift in cell membrane surface charges that occur during the early phases of differentiation and it modulates hyperpolarizing K channels by increasing intracellular Ca. The simultaneous onset of both mechanisms prevents alterations in cell differentiation. We propose that cells are normally protected against electromagnetic insult. Pathologies may arise, however, if intracellular Ca regulation or K channel activation malfunctions.

Biophys J, November 2001, p. 2580-2589, Vol. 81, No. 5
© 2001 by the Biophysical Society   0006-3495/01/11/2580/10  $2.00