Sonodynamically induced antitumor effect of 4-formyloximethylidene-3-hydroxy-2-vinyl-deuterio-porphynyl(IX)-6,7-dia spartic acid (ATX-S10).

The sonodynamically induced antitumor effect of 4-formyloximethylidene-3-hydroxy-2-vinyl-deuterio-porphyn yl(IX)-6,7-diaspartic acid (ATX-S10) was investigated. Both in vitro and in vivo antitumor effects were tested in combination with ultrasound at 2 MHz. The rate of ultrasonically induced damage to isolated sarcoma 180 cells in air-saturated suspension was enhanced two-fold with 80 microM ATX-S10. This enhancement was significantly inhibited by histidine, which may suggest that it was mediated by ultrasonically induced oxidation. The coadministraion of 25 mg/kg ATX-S10 followed by ultrasonic exposure at 2 MHz stopped the growth of implanted colon 26 tumors at an intensity at which ultrasound alone showed only a slight antitumor effect.