Inhibition of the proliferation of Ehrlich ascites tumor cells by hydrostatic pressure

The effect of high pressure on the viability of Ehrlich ascites tumor cells was examined. The tumor cells were subjected to various pressures (0.1-150 MPa) for 30 min at 37 degrees C. The viability of pressure-treated cells was examined by the dye exclusion method. The number of stained cells increased significantly at pressures above 130 MPa. In addition, the pressure-treated cells were intraperitoneally inoculated into the mice. The tumor cells which were subjected to pressures below 110 MPa proliferated in the peritoneal cavity of the mice, so that the mice died. In contrast, the mice, which were inoculated with the tumor cells treated at pressures above 130 MPa, remained alive. These results suggest that the destruction of the tumor cells begins to occur at about 130 MPa.