Motonori Okino

Optimal Electric Conditions in Electrical Impulse Chemotherapy

The relationship was examined between the tumoricidal effect and the electrical variables of in vivo electrical impulse chemotherapy. Donryu rats subcutaneously inoculated with AH‐109AY hepatocellular carcinomas were given a single high‐voltage electrical impulse of varying voltage and duration, 30 min after an intramuscular injection of 4 mg/kg bleomycin. As the voltage (V) was increased from 0 to 5 kV, the tumoricidal effect (E) increased in proportion to the square of the voltage. As the pulse duration (D) was increased from 2.5 to 5.8 ms, the tumoricidal effect increased in direct proportion to it. Combining these results yielded the formula, E=γV2D, which indicates that tumoricidal efficacy was proportional to the applied electrical energy. When the electrical energy was kept constant while varying the voltage and duration of pulse, the anticancer effect was the same, confirming this relationship for lower energy levels.

The effects of a single high voltage electrical stimulation with an anticancer drug onin vivo growing malignant tumors

Giving a high voltage electrical stimulation (5 kv/cm, 2 msec) under bleomycin administration (5 mg/body, im) resulted in a significant size decrease of subcutaneously inoculated AH-109A hepatocellular carcinomas in Donryu rats. The tumor size decreased to an average 17 per cent of the initial mass 4 days after the treatment and the average survival period was extended to almost 200 per cent of that of the control. However, neither high voltage electrical stimulation nor bleomycin administration alone demonstrated an anticancer effect. It was thus concluded that the concomitant use of a high voltage electrical stimulation and an anticancer drug has the potential to be effectively applied in cancer treatment.