[Increase in the generation of superoxide radicals and in the inhibitory effect on Yoshida sarcoma of anthracycline antitumor agents by ultrasound].
The antitumor effects of ultrasonic (US) irradiation in combination with the administration of an anthracycline drug, such as adriamycin and THP-adriamycin, were investigated from a viewpoint of the generation of superoxide radicals (SOR). In the in vitro experiments, the generation of SOR by US irradiation was measured by the amount of cytochrome c reduced. The addition of the drug stimulated the generation of SOR by US irradiation. In the in vivo experiments, Donryu rats inoculated subcutaneously by Yoshida sarcoma were treated with US irradiation in combination with the drug. During US irradiation, the temperature of the rat tissue irradiated was kept below 37 degrees C to avoid thermal effects. To know the optimum timing of US irradiation after the administration of the drug, the drug concentrations in the tumor and blood were determined and the time course of drug concentrations was analyzed pharmacokinetically. The effects of drugs and/or US irradiation showed antitumor activity judged by the growth of the tumor size or the survival time of rats. The combination treatments of US irradiation with the drug marked additional or synergistic effects on Yoshida sarcoma. Considering the relationship between the antitumor effect in vivo and the generation of SOR in vitro, the increase of anti-tumor effect of US irradiation by the anthracycline drug may be caused by the stimulation of the generation of SOR.
Yumita
N
N
Nishigaki
R
R
Umemura
K
K
Umemura
S
S
D000818:Animals; D003131:Combined Modality Therapy; D004317:Doxorubicin / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D005609:Free Radicals; D008297:Male; D009368:Neoplasm Transplantation; D051381:Rats; D012517:Sarcoma, Yoshida / Q000188:drug therapy / Q000628:therapy*; D013268:Stimulation, Chemical; D013481:Superoxides; D014464:Ultrasonic Therapy
D005609:Free Radicals; D013481:Superoxides; D004317:Doxorubicin; C027260:pirarubicin