THE ROLE OF COHERENCE TIME IN THE EFFECT OF MICROWAVES ON ORNITHINE DECARBOXYLASE ACTIVITY

Previously, we demonstrated the requirement for a minimum coherence ti me of an applied, small amplitude (10 muT) ELF magnetic field if the f ield were to produce an enhancement of ornithine decarboxylase activit y in L929 fibroblasts. Further investigation has revealed a remarkably similar coherence time phenomenon for enhancement of ornithine decarb oxylase activity by amplitude-modulated 915 MHz microwaves of large am plitude (SAR 2.5 W/kg). Microwave fields modulated at 55, 60, or 65 Hz approximately doubled ornithine decarboxylase activity after 8 h. Swi tching modulation frequencies from 55 to 65 Hz at coherence times of 1 .0 s or less abolished enhancement, while times of 10 s or longer prov ided full enhancement. Our results show that the microwave coherence e ffects are remarkably similar to those observed with ELF fields. (C)19 93 Wiley-Liss, Inc.