Direct power-frequency electric field effects on mammalian endocrine tissue.

A number of studies have investigated the in vivo biological effects of power-frequency electric fields (EF). Direct effects of EF on mammalian tissues, however, have rarely been reported. We now report that a 60-Hz EF can directly enhance the steroidogenic response of superfused rat adrenocortical tissue. The EF did not influence basal steroidogenic activity, however, the corticosterone response to 10 mU of ACTH was almost doubled by an unperturbed 1000 kV/m EF during the initial 2 hr of exposure and was enhanced fourfold by 5.5 to 7 hr of exposure with a 10 kV/m EF. Other EF intensities (e.g., 5 and 100 kV/m) were without effect at these times. Turning the 1000 kV/m EF on and off at 30-min intervals did not influence the initial enhanced steroidogenic response but did cause an additional two- to threefold elevation in the response following 5.5-7 hr of exposure. It is not clear what EF exposure parameters or mechanisms were primarily responsible for these bioeffects, but it appears that direct exposure of mammalian endocrine tissue to a 60-Hz EF is capable of significantly influencing important cellular processes.