We report the transfer of the activity of 4-phorbol-12-beta-myristate-13-acetate (PMA) by electronic means. Neutrophils were placed at 37 degrees C on one coil attached to an oscillator, while PMA was placed on another coil at room temperature. The oscillator was then turned on for 15 min, after which cells were usually further incubated for up to 45 min at 37 degrees C before measurement of reactive oxygen metabolites (ROMs) production. In 20 blind experiments, PMA thus 'transmitted' induced ROM production. ROM were not induced when: (1) PMA vehicle or 4-alpha-phorbol 12,13-didecanoate (an inactive PMA analogue) were transmitted; (2) the oscillator was switched off; (3) superoxide dismutase or protein kinase C inhibitors were added to cells before transmission. These results suggest that PMA molecules emit signals that can be transferred to neutrophils by artificial physical means in a manner that seems specific to the source molecules.