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Molecular Mechanisms of the Effect of Ultrasound on the Fibrinolysis of Clots

Overview
Publisher Elsevier
Specialty Hematology
Date 2015 Jan 27
PMID 25619618
Citations 12
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Abstract

Background: Ultrasound accelerates tissue-type plasminogen activator (t-PA)-induced fibrinolysis of clots in vitro and in vivo.

Objective: To identify mechanisms for the enhancement of t-PA-induced fibrinolysis of clots.

Methods: Turbidity is an accurate and convenient method, not previously used, to follow the effects of ultrasound. Deconvolution microscopy was used to determine changes in structure, while fluorescence recovery after photobleaching was used to characterize the kinetics of binding/unbinding and transport.

Results: The ultrasound pulse repetition frequency affected clot lysis times, but there were no thermal effects. Ultrasound in the absence of t-PA produced a slight but consistent decrease in turbidity, suggesting a decrease in fibrin diameter due solely to the action of the ultrasound, likely caused by an increase in protofibril tension because of vibration from ultrasound. Changes in fibrin network structure during lysis with ultrasound were visualized in real time by deconvolution microscopy, revealing that the network becomes unstable when 30-40% of the protein in the network was digested, whereas without ultrasound, the fibrin network was digested gradually and retained structural integrity. Fluorescence recovery after photobleaching during lysis revealed that the off-rate of oligomers from digesting fibers was little affected, but the number of binding/unbinding sites was increased.

Conclusions: Ultrasound causes a decrease in the diameter of the fibers due to tension as a result of vibration, leading to increased binding sites for plasmin(ogen)/t-PA. The positive feedback of this structural change together with increased mixing/transport of t-PA/plasmin(ogen) is likely to account for the observed enhancement of fibrinolysis by ultrasound.

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References
1.
Stone M, Frenkel V, Dromi S, Thomas P, Lewis R, Li K . Pulsed-high intensity focused ultrasound enhanced tPA mediated thrombolysis in a novel in vivo clot model, a pilot study. Thromb Res. 2007; 121(2):193-202. PMC: 2169501. DOI: 10.1016/j.thromres.2007.03.023. View

2.
Suchkova V, Siddiqi F, Carstensen E, Dalecki D, Child S, Francis C . Enhancement of fibrinolysis with 40-kHz ultrasound. Circulation. 1998; 98(10):1030-5. DOI: 10.1161/01.cir.98.10.1030. View

3.
Alonso A, Della Martina A, Stroick M, Fatar M, Griebe M, Pochon S . Molecular imaging of human thrombus with novel abciximab immunobubbles and ultrasound. Stroke. 2007; 38(5):1508-14. DOI: 10.1161/STROKEAHA.106.471391. View

4.
Pieters M, Hekkenberg R, Barrett-Bergshoeff M, Rijken D . The effect of 40 kHz ultrasound on tissue plasminogen activator-induced clot lysis in three in vitro models. Ultrasound Med Biol. 2004; 30(11):1545-52. DOI: 10.1016/j.ultrasmedbio.2004.08.028. View

5.
Chuang Y, Cheng P, Chen S, Ruan J, Li P . Effects of ultrasound-induced inertial cavitation on enzymatic thrombolysis. Ultrason Imaging. 2010; 32(2):81-90. DOI: 10.1177/016173461003200202. View