NONLINEAR DEPENDENCE OF THE DIELECTRIC-PROPERTIES OF CHICK-EMBRYO MYOBLAST MEMBRANES EXPOSED TO A SINUSOIDAL 50 HZ MAGNETIC-FIELD

Primary chick embryo myoblasts can be a useful tool for studying the developmental events which accompany myoblast differentiation, particularly myoblast membrane fusion. To determine whether the electrical properties and/or fusion in these systems are affected by 50 Hz magnetic fields, chick embryo myoblast cultures were exposed to B-field intensities ranging from 1 to 10 mT. The electrical parameters of the myoblasts, i.e. membrane conductivity, membrane permittivity and the conductivity of the cell interior (cytosol) were determined by the analysis of conductivity dispersion data in the radio frequency range (10 kHz-100 MHz). Preliminary results indicate that the time of fusion (60 h) is not affected by these fields, but that the absolute values of the two membrane electrical parameters are affected. In particular, a B-field intensity-dependent decrease was observed. The maximum effect resulted after a 1 h exposure to a magnetic flux density of about 5 mT. The conductivity of the cytosol remained unchanged. These data seem to indicate that exposure to 50 Hz magnetic fields affects both static and dynamic membrane properties in primary chick embro myoblasts.