TY - GEN A1 - Greif, G. A1 - Mrowietz, Christof A1 - Meyer-Sievers, H. A1 - Ganter, M. A1 - Jung, Friedrich A1 - Hiebl, Bernhard T1 - Differences in human and sheep platelet adherence, aggregation and activation induced by glass beads in a modified chandler loop-system T2 - Clinical Hemorheology and Microcirculation N2 - In human cardiovascular research, sheep in particular are used as a large animal model in addition to pigs. In these animals, medical products, developed and tested for human medical purposes, are almost exclusively used in interventional studies. Therefore, the extent to which platelets from human and ovine blood differ in terms of adherence, aggregation and activation after a 4- or 8-minutes exposure to glass was investigated. Testing was performed with platelet-rich plasma (PRP) and a modified chandler loop-system, with 4- and 8-minute blood-material exposure times corresponding to 20 and 40 test cycles, respectively, through the entire silicone tube loop of the test system. In sheep and human PRP, contact with the silicone tubing resulted in a decrease in platelet count after 4 minutes and 20 test cycles, respectively. Four more minutes (20 additional test cycles) caused a further decrease of the platelet count only in sheep PRP. When the silicon tube was partly filled with glass beads, these effects were more pronounced and stronger in sheep then in human PRP. The mean platelet volume, which was used as parameter for platelet aggregation, did not change over time in human PRP without glass exposure. With glass exposure in human and sheep PRP the mean platelet volume increased within 40 test cycles, but this increase was stronger in sheep than in human PRP. Regarding activation behavior, the activation markers CD62P and CD63 were detectable only in < 30% (sheep) and < 45% (human) of platelets, whereas after 8 min of glass exposure, the proportion of CD62P+ and CD63+ cells was more increased than before only in sheep. These results indicate that ovine platelets adhere more strongly to glass and show stronger aggregation behavior after glass contact than human platelets, but that ovine and human platelets differ only slightly in activability by glass. KW - Sheep KW - platelet KW - activation KW - platelet volume KW - CD42a KW - CD61 KW - CD62P KW - CD63 Y1 - 2021 UR - https://content.iospress.com/articles/clinical-hemorheology-and-microcirculation/ch219104 U6 - https://doi.org/10.3233/CH-219104 SN - 1875-8622 SN - 1386-0291 VL - 79 IS - 1 SP - 129 EP - 136 ER -