INFLUENCE OF COMBINED AC-DC MAGNETIC-FIELDS ON FREE-RADICALS IN ORGANIZED AND BIOLOGICAL-SYSTEMS - DEVELOPMENT OF A MODEL AND APPLICATION OF THE RADICAL PAIR MECHANISM TO RADICALS IN MICELLES

The effect of an alternating current (AC) magnetic field (MF) on radic al behavior is identical to that exerted by a direct current (DC) held of the same instantaneous strength provided that the frequency is low enough in comparison with radical pair dynamics. This criterion is ea sily met by environmental fields. In general, combined AC/DC fields wi ll lead to increased radical concentrations and oscillating free radic al concentrations. Interestingly, the frequency of oscillation for rad ical concentration seldom follows exactly the pattern of the external AC component of the MF. Even the simple case of an AC-only field at 60 Hz can lead to oscillations in radical concentrations at 120 Hz. The concentration time dependence patterns can be even more complex when t he singlet and tripler levels of the radical pair are not degenerate. Further, the effects can change dramatically depending upon the absolu te and relative values of the AC and DC components, thus providing a p ossible explanation for MF windows for certain effects reported experi mentally. Effects on the average radical concentration are probably re levant only for fields higher than about 0.1 gauss. Oscillating radica l concentrations may influence signal transduction processes or other cellular mechanisms; at the present time there is not enough knowledge available to establish a reasonable threshold for these types of effe cts. This contribution aims at providing a solid foundation to guide t he experimentalist in the design of meaningful experiments on the poss ible role of MF perturbations of radical chemistry on biological respo nse.