Butler S P, Kader K L, Owen J, Wang T S, Fawwaz R A, Alderson P O
Department of Radiology, Columbia-Presbyterian Medical Center, New York, New York 10032.
J Nucl Med. 1991 Mar;32(3):461-7.
The thrombus localizing properties of indium-111-recombinant tissue plasminogen activator (111In-rt-PA) have been investigated in an effort to achieve prompt and accurate detection of thrombi. Unlike previous studies with rt-PA, the active plasminogen catalytic site was permanently inhibited with peptides of chloromethyl ketone so that the radiotracer binds to fibrin without causing fibrinolysis. Thrombi were created in the external jugular vein of 14 male New Zealand white rabbits followed by injection of 111In-rt-PA. The agent cleared rapidly in vivo with a half-time of 4.6 min. The thrombus: blood ratio in nonheparinized rabbits (n = 7) was 6.39 +/- 0.86. The ratio in heparinized rabbits (n = 4) was 3.11 +/- 0.23. Thrombi were clearly visible in the planar images of both groups 1 hr postinjection. The combination of rapid thrombus localization and positive images, especially in the presence of anticoagulation, suggests that further work is warranted with rt-PA thrombus imaging.
为了实现对血栓的快速准确检测，人们对铟 - 111重组组织型纤溶酶原激活剂（¹¹¹In - rt - PA）的血栓定位特性进行了研究。与以往对rt - PA的研究不同，活性纤溶酶原催化位点被氯甲基酮肽永久抑制，这样放射性示踪剂就能与纤维蛋白结合而不引起纤维蛋白溶解。在14只雄性新西兰白兔的颈外静脉中形成血栓，随后注射¹¹¹In - rt - PA。该制剂在体内清除迅速，半衰期为4.6分钟。未用肝素处理的兔子（n = 7）的血栓与血液比值为6.39±0.86。用肝素处理的兔子（n = 4）的比值为3.11±0.23。注射后1小时，两组的平面图像中血栓均清晰可见。快速的血栓定位和阳性图像的结合，尤其是在存在抗凝的情况下，表明rt - PA血栓成像值得进一步研究。
