Exposure to extremely low frequency magnetic fields affects insulin-secreting cells.

To evaluate the effects of extremely low frequency magnetic field (ELFMF) on beta-cell survival and function, we cultured a hamster-derived insulin-secreting cell line (HIT-T15), which exhibits responsiveness to glucose in a semi-physiological range, under exposure to sham and ELFMF conditions, and assessed cell survival and function. We used our previously developed ELFMF exposure unit (a sinusoidal magnetic field at a frequency of 60 Hz, 5 mT) to culture cells under exposure to ELFMF conditions. We found that exposure to ELFMF for 5 days in the absence of glucose increased cell number, exposure for 2 days in the absence of glucose and for 5 days with 100 mg/dl glucose increased the insulin secretion to the culture medium, and exposure for 2 and 5 days with 40 and 100 mg/dl glucose increased intracellular insulin concentration in HIT-T15 cells. The increase in cell number under apoptotic culture conditions by exposure to ELFMF could lead to new therapeutic concepts in the treatment of diabetes. The ELFMF-induced increase in intracellular insulin concentration could be utilized to develop culture conditions to enhance intracellular insulin concentration in insulin-secreting cells that would be useful for cell transplantation to cure diabetes mellitus. (c) 2007 Wiley-Liss, Inc.