Effects of ultrasound exposure in vitro on neuroblastoma cell membranes

Mechanisms of action of ultrasound on cell membranes were studied on two murine C1300 neuroblastoma cell lines of minimum genetic diversity. Cavitation was established in rotating polystyrene centrifuge tubes by 1 MHz cw ultrasound; exposure time was 5 minutes. NS20Y and N2A cells exposed in suspension responded similarly by 86Rb+ transport and Na+-K+-ATPase activity assays, but differently by trypan blue dye exclusion and lysis assays. This indicates similar overall damage to the cell membranes, despite use of trypsin to release N2As only. Primary evidence of damage was lysis of NS20Ys and permeabilization of N2As. These results indicate that the same ultrasound exposure conditions can produce different effects in cells that differ in their membrane properties.