CYCLIC-AMP RESPONSE IN CELLS EXPOSED TO ELECTRIC-FIELDS OF DIFFERENT FREQUENCIES AND INTENSITIES

The action on intracellular cyclic AMP (cAMP) of therapeutically used 4000-Hz electric fields was investigated and compared with 50-Hz data. Cultured mouse fibroblasts were exposed for 5 minutes to 4000-Hz sine wave internal electric fields between 3 mV/m and 30 V/m applied withi n culture medium. A statistically significant decrease in cellular cAM P concentration relative to unexposed cells was observed for fields hi gher than 10 mV/m. The drop in cAMP was most pronounced at lower field strengths (71 % of controls at 30 mV/m) and tended to disappear at hi gher field strengths. An increase of cAMP content was observed with 50 -Hz electric fields, as was also the case when 4000-Hz fields were mod ulated with certain low frequencies.