Ultrasonic production of reversible changes in the electrical parameters of isolated frog skin

Abstract

Isolated frog skin was irradiated with 1-MHz noncavitating focused ultrasound, intensity range 1-100 W/cm2, in an adaptation of the Ussing chamber providing continuous perfusion of the specimen. The electrical parameters of the skin, viz., the membrane potential (MP) and the short circuit current (SCC), were monitored continuously before, during and after the acoustic exposure. The magnitudes of the ultrasonically induced changes, in both parameters, were proportional to the acoustic intensity, though the MP decreased while the SCC increased. Unlinking of the 2 electrical parameters occurs in that their time courses in response to the ultrasound differ, i.e., the SCC increases continuously for exposures of 0.5 s and longer while the MP reaches its maximum within 0.5 s and is not altered with increased duration of exposure.