Membrane damage effect of therapeutic ultrasound on Ehrlich ascitic tumor cells.
OBJECTIVE
The biologic effects and the underlying mechanisms of Ehrlich ascitic tumor (EAT) cells induced by ultrasound were investigated in this study.


METHODS
Cells were subjected to ultrasonic irradiation with a frequency of 2.17 MHz and an intensity of 3 W/cm(2) for variable periods of time. Trypan blue exclusion was used to detect the integrity of cellular membrane; the membrane permeability was investigated by the incorporation of fluorescein isothiocyanate dextran during ultrasound exposure; and the cell membrane ultrastructure changes were observed under a scanning electron microscope. The potential mechanism was estimated from the generation of hydroxyl radicals, the lipid peroxidation levels, and intracellular reactive oxygen radicals production.


RESULTS
The cell membrane damage effects induced by ultrasound increased with a prolonged exposure time; the fluorescent rates of the cells irradiated with ultrasound for 30 and 60 seconds were 11.46% and 18.50%, respectively; the amount of hydroxyl radicals in 30 (26.10 U/mL) and 60 seconds (28.47 U/mL) were significantly enhanced, compared with the control group (24.44 U/mL); then, the level of lipid peroxidation was also changed from 0.27 to 0.54 (30 seconds) and 1.21 nmol/mL (60 seconds).


CONCLUSIONS
Shear forces and free radicals produced by acoustic cavitation may play important roles in these actions.
Hao
Qiao
Q
College of Life Sciences and Natural Pharmaceutical Chemistry, Shaanxi Normal University, Xi'an China.
Liu
Quanhong
Q
Wang
Xiaobing
X
Wang
Pan
P
Li
Tao
T
Tong
Wan Yan
WY
D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000000981:diagnostic imaging* / Q000628:therapy*; D002462:Cell Membrane / Q000000981:diagnostic imaging*; D002463:Cell Membrane Permeability; D002470:Cell Survival; D016650:Fluorescein-5-isothiocyanate / Q000494:pharmacology; D017665:Hydroxyl Radical; D015227:Lipid Peroxidation; D051379:Mice; D008855:Microscopy, Electron, Scanning; D017382:Reactive Oxygen Species; D013010:Sonication; D016896:Treatment Outcome; D014343:Trypan Blue / Q000494:pharmacology; D014464:Ultrasonic Therapy / Q000379:methods*; D014463:Ultrasonography
D017382:Reactive Oxygen Species; D017665:Hydroxyl Radical; D016650:Fluorescein-5-isothiocyanate; D014343:Trypan Blue