Effects of Duty-Cycle Distribution on Pulsed Magnetic Field Modulation of Lsa Tumors in Mice

Abstract

For the present study, 8-10 week old male and female C57NA/Fe mice were each injected with 10⁶ cells of LSA ascites tumor. On day 5, the mice received 5 mg/kg of BCNU, were sorted into sexually distinct groups of 4-6 animals, and then placed into an asymmetric 15 Hz pulsed magnetic field for two additional days. The fields were turned on for cycles of 1/1, 2/2, 4/4, 6/6, 12/12, and 24/0 Hr. The results indicated that the system can respond selectively to the various 50% duty cycles, and that it ignores the 100% duty cycle. The responses were uniformly positive for the 12/12 and negative for the 6/6 Hr regimes, but were strongly sexually dimorphic for other regimes.