Enhancement of protein synthesis by neuroblastoma cells exposed to ultrasound cavitation

Abstract

Enhancement of the cavitational effect of iodine release from sodium iodide solution during repetitive 1-MHz tone burst excitation of the solution of a rotating test tube has been reported. [V. Ciaravino, H. G. Flynn, and M. W. Miller, Ultrasound Med. Biol. 7, 159–166 (1981)]. This enhancement was attributed to concurrent operation of two mechanisms: depletion of small nuclei from the cw mode size distribution generated during a tone burst, and survival from the previous tone burst of small nuclei lying in the same size range that is depleted in the cw mode. Twenty-four hours after exposing C1300 neuroblatoma cells (N2A) in rotating tubes to 1-MHz ultrasound tone bursts [1:1, durations from 6 to 600 ms; 3.4 W/cm2 spatial peak, burst average intensity, and 5 min total treatment duration (on + off periods)] at 37°C, enhancement of protein synthesis compared to control cells was observed. Protein synthesis was measured by uptake of H3-leucine. The similarity between results observed for cavitation-stimulated iodine release and cellular protein synthesis is highly suggestive of cavitation as the cause for this biological effect. [Work supported by PHS.]