Ion-protein dissociation predicts 'windows' in electric field-induced wound-cell proliferation

There are many experiments showing that weak, non-thermal electric fields influence living tissues. In many cases, biological effects display 'windows' in biologically effective parameters of electric fields: most dramatic is the fact that relatively intense electric fields sometimes do not cause appreciable effect, while smaller fields do. Linear resonant physical processes do not explain frequency windows in this case. Both frequency and amplitude windows are evident from experiments on human dermal fibroblasts in a collagen matrix. For this in vitro model of skin, exposure to extremely low frequency (ELF) electric fields in the frequency range 10-100 Hz and the amplitude range of 0-130 mu A/cm(2) macroscopic current density demonstrates such unusual 'window' behavior. Amplitude window phenomena suggest a nonlinear physical mechanism. We consider non-linear quantum-interference effects on protein-bound substrate ions: These ions experience, due to electric fields in the media or biological tissue as small as 1 mV/m, electric gradients produced by polarized binding ligand atomic shells. The electric gradients cause an interference of ion quantum states. This ion-interference mechanism predicts specific electric-field frequency and amplitude windows within which fibroblast proliferation occurs. (C) 2000 Elsevier Science B.V. All rights reserved.