SONOCHEMICALS INCREASE THE MUTATION FREQUENCY OF V79 CELLS IN-VITRO

Phosphate buffered saline (PBS) was insonated or sham-insonated (1 MHz , 35 W/cm(2), continuous, wave, 30 min) in rotating (200 rpm) sterile polystyrene culture tubes. After treatment, the PBS was used immediate ly to suspend washed Chinese hamster V79 cells in vitro. Cells were in cubated in the PBS at 37 degrees C for 15 min and then transferred to complete growth medium. Some insonation regimens also involved the inc lusion of Albunex(R) (ALX; an ultrasound microbubble contrast agent) t o enhance ultrasound-induced inertial cavitation, Following exposure t o the pretreated PBS and 6 d of subculture in complete medium, the cel ls were assayed for plating efficiencies and mutation frequencies (res istance to 6-thioguanine), X-rays (3 Gy) served as a positive control. Cells exposed to insonated PBS with or without ALX or x-rays had stat istically significantly elevated mean mutation frequencies (4.37 +/- 0 ,97, 4.54 +/- 1.00, and 24.28 +/- 3.83 mutant colonies/10(6) viable ce lls, respectively) relative to corresponding control regimens (ultraso und sham, 2.44 +/- 0.56; x-ray sham, 2.96 +/- 0.88 mutant colonies/10( 6) viable cells. The data supported the hypothesis that sonochemicals resulting from inertial cavitation have mutagenic potential, (C) 1998 World Federation for Ultrasound in Medicine & Biology.