Pulsed Magnetic Field Modulation of Lsa Tumors in Mice

Abstract

To determine whether the same pulsed magnetic fields used to stimulate bone healing in recalcitrant fractures would alter the course of malignant tumor development, we have undertaken these studies in mice with LSA lymphoma. LSA is a virulent ascites tumor with a TD₅₀ of 2 cells, producing death in 7.5 days. C57BL mice were placed in a pulsing electromagnetic field after inoculation with the tumor, and after inoculation with the tumor plus injection with 5 mg/kg BCNU, a potent chemotherapeutic agent. Mice were examined at the time of death. The fields potentiated the effects of BCNU in some respects, and inhibited the effects in others. By themselves, the fields did not increase survival time, but did considerably reduce the size of the spleen, and its infiltration by tumor cells. The fields also reduced the involvement of the liver and lymph nodes of affected animals.