Objective:To determine whether ultrasound could enhance the cytotoxicity of taxol against human ovarian cancer cells HO-8910PM

a cell line with highly metastatic potential.Methods:Cell-killing attributed to ultrasound was determined by tetrazolium assay

and then an insonation level with a slight cytotoxicity was singled out for investigating the synergism.Such a level of sonication was co-used with taxol to deacti-vate cancer cells.Results:Inhibition rates in groups Taxol and Taxol+US

were12.4% vs11.7%(P>0.05)when taxol waswith a concentration of 6 μg/ml and were 27.8% vs 42.0%(P<0.05)when taxol was 18 μg/ml

respectively.Qualitative evalua-tion confirmed that there existed a synergism between taxol and ultrasound

while the content of taxol was 18 μg/ml.Conclu-sion:Ultrasound potentiated the cytotoxicity of taxol against ovarian cancer cells

and the synergism occurred only when the concentration of taxol was above the critical level.