Temperature dependence of ultrasound‐induced cell killing: The role of membrane fluidity

Abstract

Chinese hamster cells in suspension were exposed to 20 kHz ultrasound (US) at 54 W/cm2 and various temperatures between 2 and 44 degrees C. Activation energies were 2.6 and 24 kcal/mole below and above 35 degrees C, respectively. Procaine, a local anaesthetic drug known to increase membrane fluidity, enhanced cellular inactivation by US above 41 degrees C, increasing the activation energy to 62 kcal/mole. The inactivation of the bacterium Salmonella typhimurium by US was also dependent on the exposure temperature, with an activation energy of 2.9 kcal/mole between 2 and 44 degrees C. These data are most simply explained by the hypothesis that membranes are a major target for cellular inactivation by US and that the fluidity of the membranes is important in this respect.

The effect of high-intensity ultrasound on cell disruption and lipid extraction from high-solids viscous slurries of Nannochloropsis sp. biomass

“…The first is through the cell wall membrane expansion and compression due to compression and rarefaction of ultrasound field. The cell membrane rigidity plays a greater role in this kind of rupture [39]. If the cell membrane is highly elastic, it can expand and shrink significantly without breaking.…”

Enhancement of Hyperthermic Cell Killing by Non-thermal Effect of Ultrasound

“…It is reported that cell lysis induced by ultrasound results from disruption of the cell membrane due to mechanical shearing stress arising from cavitation (Hughes and Nyborg 1962) . Procaine, a local anaesthetic acting on the membrane, has been shown to enhance the response to hyperthermia (Yau 1979) andultrasound (Ben-Hur andGreen 1982) . Procaine, a local anaesthetic acting on the membrane, has been shown to enhance the response to hyperthermia (Yau 1979) andultrasound (Ben-Hur andGreen 1982) .…”