Objective To observe the bio-effects of SMMC-7721 cells treated with low-frequency ultrasound and microbubble agent to offer the clinic application theory basis of ultrasound.Methods Cells were divided into four groups : A,control;B,pure microbubble agent;C,pure ultrasound,according to the exposure time,group C was subdivided to C1(exposed for 60 s),C2(exposed for 90 s),C3(exposed for 120 s) and C4(exposed for 150 s);D,low-frequency ultrasound combined with microbubble agent,according to the exposure time,group D was subdivided to D1(exposed for 60 s),D2(exposed for 90 s),D3(exposed for 120 s) and D4(exposed for 150 s).The survival rate of VEC-304 cells was observed by MTT colorimetric assay.Visible spectrophotometric was applied to determine ROS and SOD.Cell apoptosis was analyzed using flow cytometry after ultrasonic exposure.Results Group C and D were obviously inhibited to proliferated,as observed by MTT colorimetric assay.The yield of ROS of group C3 and D3 was much higher than that of group A,B and the yield of SOD of group C3 and D3 was much lower than that of group A,B.The apoptosis rate was found to reach(15.24±2.16)% in group C3 and(27.31±4.14)% in group D3 with FCM.Conclusions Low-frequency ultrasound combined with micro-bubble agent can induce injury and apoptosis of SMMC-7721 cells,probably due to the increase of the activity of ROS in cultured liquid. |