Effect of ultrasound on the permeability of D2O through cellulose membranes.

The effect of ultrasound energy on the permeability of water through cellulose membranes was studied using deuterium oxide (D2O) as a tracer. The same membrane was used for control (no ultrasound) and ultrasound experiments in a sequential reversal design. Transfer of D2O to a 2% albumin solution was measured in a glass dializing cell with membrane area of 11 cm2. Ultrasonic energy was supplied for 45 min by a hydrosonic bath (Linden Laboratories) at an intensity of 0.18 watt/cm2, an energy level commonly used for therapeutic purposes. Statistical analysis showed a significant increase in water transfer due to the ultrasound treatment irrespective of the sequence of application of ultrasound. It was concluded that ultrasound energy increases water permeability through cellulose dializing membranes. Whether or not increased water permeability is the operating mechanism underlying the beneficial effects of ultrasonic bath therapy remains unanswered.