Effect of acoustic cavitation on platelets in the presence of an echo-contrast agent.
A suspension of human platelets in autologous plasma or buffer solution with and without a microbubble echo-contrast agent was exposed in vitro to 730 W/cm2 (ISPPA) ultrasound pulses of duration 40-160 microseconds at 1 MHz and 20-Hz pulse repetition frequency. Inertial cavitation occurring within the samples was monitored during the exposures and a measure of average cavitational activity was calculated for each 5-min exposure. This quantity, with the other acoustic parameters, accounted for up to 75% of the variation in the destruction of platelets as measured by Coulter counter and 83.5% of the release of bound radiolabel using a multiple-interaction statistical model. When the echo-contrast agent was absent, negligible cavitation occurred and the amount of platelet destruction was statistically indistinguishable from sham (no-ultrasound) exposures. Therefore, microbubble echo-contrast agents may interact with ultrasound to cause platelet lysis through the mechanism of inertial cavitation.
Everbach
E C
EC
Department of Engineering, Swarthmore College, PA 19081-1397, USA.
Makin
I R
IR
Francis
C W
CW
Meltzer
R S
RS
D000162:Acoustics; D000418:Albumins; D001792:Blood Platelets / Q000473:pathology*; D003287:Contrast Media; D006461:Hemolysis; D006801:Humans; D016018:Least-Squares Analysis; D016014:Linear Models; D008863:Microspheres; D015233:Models, Statistical; D014463:Ultrasonography / Q000009:adverse effects*
D000418:Albumins; D003287:Contrast Media