Exposure of C3H/Bi female mice with mammary carcinoma to pulsed magnetic fields.

Pulsed magnetic fields (PMF) have already proved to have a certain influence not only on leucocytes in vitro but also on thymocytes in vivo. C3H/Bi tumoral female mice were either exposed to 12 Hz or 460 Hz, and to 6, 9 or 20 mT PMF just two weeks after the tumors had appeared and this until the moment they died. Actually, all the survival times as well as the average weights of spleens lungs, and tumors were then taken into account at the very death of the mice. In a general way there happened to be no difference in spite of the different frequencies used and the rates of lungs with metastases were not at all influenced by the exposure itself. However a 3-hour-exposure once a week could increase the mean survival times whereas a 15-minute-exposure to a 6 mT PMF twice a week gave lighter spleens than those of the controls and an exposure either to 9 mT or to 20 mT gave heavier tumors in general.