Effects of Lithotripter-Generated High Energy Shock Waves on Mammalian Cells in Vitro

Abstract

The effects of high energy shock waves on an established human prostatic carcinoma cell line (PC-3) were investigated. HESW were administered to PC-3 cell suspensions using an electrohydraulic lithotripter (Dornier HM3). Experimental variables included the number of shocks to which the cells were exposed, spark generator potential, and the position of the cell sample in the acoustic field. Two types of cellular damage were observed: immediate cell destruction (lysis) as measured by electronic particle counting and the loss of reproductive capacity (viability) among the remaining cells as determined by colony formation assay. Over the range of the experimental variables studied, cell lysis was dependent to a greater extent on the number of shocks administered than the generator potential. Viability was affected less but was also dependent on both the generator potential and shock number. Cell lysis was strongly dependent on the position of the sample in the acoustic field with the extent of damage increasing as the sample was moved along the central axis of the shock wave from the f2 focus towards the electrodes. Possible mechanisms of damage and the relationship of the in vitro effects to the damage observed in normal tissues of patients undergoing extracorporeal lithotripsy for kidney stone disease are discussed.