ANALYSIS OF THE EFFECT OF A 60 HZ AC FIELD ON HISTAMINE-RELEASE BY RAT PERITONEAL MAST-CELLS

Reports have indicated effects of electromagnetic fields on inflammato ry processes in vivo. To begin a systematic approach toward separating and examining the many components of such responses, we created and t ested a temperature-controlled device to develop 5 mT 60 Hz magnetic f ields for studies of the effects of fields on mast cells, a key compon ent in acute inflammatory responses. Such fields have been reported to modulate cell activity, including changes in membrane function, in va rious systems. The magnetic field was generated using a solenoid and c alibrated with an induction probe. Tests of mast cell function were de termined by histamine release response to stimulation by compound 48/8 0, using both an ''expose then test'' and a ''test during exposure'' p rotocol. Aliquots not treated with 48/80 were used to evaluate field t reatment effects on spontaneous histamine release. Freshly harvested r at peritoneal mast cells were exposed to the magnetic field for period s of 30 min to 2 h at 37 degrees C. They showed no significant degranu lation during treatment, nor did they show reduced sensitivity to the degranulating agent 48/80. These observations are consistent with a mo del in which such processes are exclusively reflexive by the cells usi ng field-independent membrane systems. This observation is very useful and was needed before examining longer term exposures in which gene e xpression in the cells might be influenced; this is the first such rep ort of in vitro exposure of purified mast cells under these conditions and will further the study of the effects of electromagnetic fields o n cell types active in acute inflammation. (C) 1998 Wiley-Liss, Inc.