Confirmation of the protective effect of cysteamine in in vitro ultrasound exposures

Armour and Corry (Radiat. Res. (1982) 89 369–380) reported that ultrasound-induced damage to in vitro Chinese hamster ovary cells was significantly reduced in the presence of cysteamine. The objective of this study was to attempt verification of this result. Four series of experiments were undertaken using in vitro cell suspensions, namely: (1) determination of the effect of cysteamine concentration on cell growth; (2) determination of the temperature dependence of ultrasonically induced cell damage; (3) determination of a dose-response relationship for the cytotoxicity of cysteamine; and (4) assessment of cell integrity and reproductive capacity in the presence or absence of cysteamine during ultrasonic exposure. Ultrasound parameters included a resonance frequency of 1 MHz, a continuous wave exposure duration of 5 min, and intensities from 0 to 21.6 W cm^?2. The results indicated a dependence of ultrasound's efficacy on the medium's temperature during insonation and a significant reduction of ultrasound efficacy in compromising cellular integrity in the presence of cysteamine.