Sonolysis of Albunex (R)-supplemented, 40% hematocrit human erythrocytes by pulsed 1-MHz ultrasound: Pulse number, pulse duration and exposure vesselrotation dependence

The hypotheses tested were that sonolysis of erythrocytes in the presence o f a gas-based ultrasound contrast agent in vitro will be related quantitati vely to the duration and number of ultrasound pulses applied using a consta nt pulse repetition period and, at least qualitatively, to the total exposu re duration (i.e., the product of pulse number x pulse duration). An object ive was to determine the influence of sample rotation during insonation on the amount of hemolysis produced under these conditions, Human erythrocytes , suspended to 40% hematocrit in autologous plasma containing 3.6% (V:V) Al bunex(R), were exposed/sham-exposed to 1-100 pulses of 1-MHz ultrasound (6. 2 MPa peak positive, 3.6 MPa peak negative acoustic pressures; I-SPTP simil ar to 800 W/cm(2)) using a 1-s pulse repetition period. Pulse durations ran ged from 20-20,000 mu s; samples were either stationary or rotated (200 rpm ) during insonation, Hemolysis was independent of vessel rotation treatment at all tested pulse durations and pulse numbers. Levels of hemolysis stati stically greater than in sham-exposed samples were obtained with greater th an or equal to 50 pulses of 20 mu s duration, and greater than or equal to 1 pulse of 200, 2000 or 20,000 mu s duration. Hemolysis increased with incr easing pulse number and poise duration. Approximately equivalent levels of hemolysis were produced by different pulse number x pulse duration combinat ions, yielding the same total exposure duration. (C) 1999 World Federation for Ultrasound in Medicine & Biology.