Ultrasonic enhancement of nitrogen mustard cytotoxicity in mouse leukemia

Mouse leukemia L1210 cells were exposed to continuous wave 2 MHz, 10 W/cm(2) ultrasound for 10 minutes while suspended in nitrogen mustard solution in vitro. Mice subsequently inoculated with these cells had longer survival times than control animals that received cells exposed to the drug but not ultrasound. Without the drug, ultrasound did not alter survival time. Tracer studies revealed increased cellular accumulation of drug under the influence of ultrasound.