Johnson Carl A, Woolley Joshua R, Snyder Trevor A, Shankarraman Venkat, Haney Elaine I, Wagner William R
Department of Bioengineering, Pittsburgh, PA, USA.
McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
Artif Organs. 2018 Dec;42(12):E427-E434. doi: 10.1111/aor.13282. Epub 2018 Sep 25.
Ovines are a common animal model for the study of cardiovascular devices, where consideration of blood biocompatibility is an essential design criterion. In the ovine model, tools to assess blood biocompatibility are limited and continued investigation to identify and apply additional assays is merited. Toward this end, the thrombelastograph, clinically utilized to assess hemostasis, was used to characterize normal ovine parameters. In addition, platelet labeling with biotin was evaluated for its potential applicability to quantify ovine platelet life span. Mean ovine thrombelastograph values were reaction-time: 4.9 min, K-time: 2 min, angle: 64.1°, maximum amplitude: 68.6mm, actual clot strength: 11.9 kd/s, and coagulation index: 1.5. Reaction time was significantly shorter and maximum amplitude, actual clot strength, and coagulation index were all significantly higher when compared to normal human thrombelastograph values suggesting some hypercoagulability of sheep blood. Biotinylation and reinfusion of ovine platelets allowed temporal tracking of the labeled platelet cohort with flow cytometry. These data indicated a mean ovine platelet life span of 188h with a half-life of 84h. The collection of these parameters for normal ovines demonstrates the applicability of these techniques for subsequent studies where cardiovascular devices may be evaluated and provides an indication of normal ovine values for comparison purposes.
绵羊是研究心血管装置的常用动物模型,其中血液生物相容性的考量是一项重要的设计标准。在绵羊模型中,评估血液生物相容性的工具有限,因此有必要持续开展研究以确定并应用更多检测方法。为此,临床上用于评估止血功能的血栓弹力图被用来测定正常绵羊的参数。此外,还评估了用生物素标记血小板在量化绵羊血小板寿命方面的潜在适用性。绵羊血栓弹力图的平均数值为:反应时间4.9分钟、K时间2分钟、角度64.1°、最大振幅68.6毫米、实际凝血强度11.9kd/s以及凝血指数1.5。与正常人类血栓弹力图数值相比,绵羊的反应时间显著更短,最大振幅、实际凝血强度和凝血指数均显著更高,这表明绵羊血液存在一定程度的高凝性。对绵羊血小板进行生物素化处理并回输后,可用流式细胞术对标记的血小板群体进行实时追踪。这些数据表明,绵羊血小板的平均寿命为188小时,半衰期为84小时。收集正常绵羊的这些参数,证明了这些技术在后续评估心血管装置的研究中的适用性,并为比较提供了正常绵羊数值的参考。