Nilsson A M, Odselius R, Roijer A, Olsson S B
Department of Cardiology, University Hospital, Lund, Sweden.
Ultrasound Med Biol. 1995;21(6):833-40. doi: 10.1016/0301-5629(95)00014-i.
We have earlier documented that ultrasound can enhance the fibrinolytic effect of streptokinase and shorten the reperfusion time under experimental conditions. The present study concerns the magnitude of the effect in relation to ultrasound frequency, intensity and exposure time. The effect of ultrasound on the structural properties of the fibrin network was evaluated by scanning electron microscopy. Whole blood clots were created and exposed to streptokinase (5000 U/mL). In paired experiments, one clot was also exposed to pulsed ultrasound. Lysis is expressed as the percentage decrease in clot weight. Clot lysis was equally affected by ultrasound in the range of 0.5 to 2.3 MHz. Below 0.5 W/cm2 no enhancing effect was observed, while intensities between 0.5 and 1.5 W/cm2 resulted in a significant enhancement of clot lysis. Intensities above 4 W/cm2 inhibited the fibrinolytic effect of streptokinase but not of rt-PA. From scanning electron microscopy there was no evidence that ultrasound disrupted the clot surface or damaged the fibrin structure.
我们之前已记录到，在实验条件下超声可增强链激酶的纤溶作用并缩短再灌注时间。本研究关注该效应与超声频率、强度及暴露时间的关系。通过扫描电子显微镜评估超声对纤维蛋白网络结构特性的影响。制备全血凝块并使其暴露于链激酶（5000 U/mL）。在配对实验中，一个凝块还暴露于脉冲超声。溶解程度以凝块重量减少的百分比表示。在0.5至2.3 MHz范围内，超声对凝块溶解的影响相同。低于0.5 W/cm2未观察到增强效应，而强度在0.5至1.5 W/cm2之间则导致凝块溶解显著增强。高于4 W/cm2的强度抑制链激酶的纤溶作用，但不抑制重组组织型纤溶酶原激活剂（rt-PA）的纤溶作用。扫描电子显微镜检查未发现超声破坏凝块表面或损伤纤维蛋白结构的证据。
