Inhibition of calcium channel activation in GH3 cells by static magnetic fields.
Voltage-activated calcium channel function was examined in cultured GH3 cells using the whole-cell patch clamp technique. Exposure to a 120 mT static magnetic field resulted in a slight reduction in the peak calcium current amplitude and shift in the current-voltage relationship. The most significant change was a slowing of the channel activation rate without any change in the inactivation rate. All changes in channel function were reversible, with return to pre-exposure values within 3 min after the field was turned off. These alterations in channel function were temperature-dependent. The present findings are consistent with a functional disruption of the intramembranous portion of the calcium channel by a magnetically induced membrane deformation.
Rosen
A D
AD
Department of Neurology, School of Medicine, State University of New York, Stony Brook 11794-8121, USA. arosen@neuro.som.sunysb.edu
D015220:Calcium Channels / Q000502:physiology*; D002460:Cell Line; D004533:Egtazic Acid / Q000494:pharmacology; D004553:Electric Conductivity; D008280:Magnetics; D008564:Membrane Potentials; D018408:Patch-Clamp Techniques; D010902:Pituitary Gland; D013779:Tetrodotoxin / Q000494:pharmacology
D015220:Calcium Channels; D013779:Tetrodotoxin; D004533:Egtazic Acid