Temperature dependence of ultrasound-induced cell killing: the role of membrane fluidity.
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.
D000818:Animals; D002460:Cell Line; D002470:Cell Survival; D006224:Cricetinae; D003412:Cricetulus; D008560:Membrane Fluidity / Q000187:drug effects; D011343:Procaine / Q000494:pharmacology; D013696:Temperature; D014465:Ultrasonics / Q000009:adverse effects*
D011343:Procaine