Glucose homeostasis in rats exposed to magnetic fields.

The development of diagnostic and therapeutic applications of magnetic fields, especially with regard to magnetic resonance imaging (MRI), draws attention to accompanying possible adverse effects. Recent investigations revealing an increase in insulin release in diabetic rats, increase in glycogen, and decrease in glucose level in rats exposed to magnetic fields, have provided the stimulus for the current studies. Rats were exposed to uniform constant magnetic fields of 10(-3) T and 10(-2) T, 1 hour each day, for a period of ten days. Blood glucose slightly increased, the release of insulin decreased, and the glucagon content increased when compared with controls. The efficiency of the hypophysis-hypothalamic system changed, as indicated by an increase in the level of growth hormone and thyroid-stimulating hormone. The content of the thyroid hormones, triiodothyronine and thyroxine, was higher between the third and seventh day of exposure. An increase in the cortisol level was also observed. The results might implicate a temporarily diabetic-like response in rats exposed to the magnetic field.