Differences in human and sheep platelet adherence, aggregation and activation induced by glass beads in a modified chandler loop-system

Issue title: 40th Conference of the German Society for Clinical Microcirculation and Hemorheology, 5-6 November 2021, Senftenberg, Germany

Guest editors: J.-H. Küpper, A. Krüger-Genge and F. Jung

Article type: Research Article

Authors: Greif, G.^a | Mrowietz, C.^a | Meyer-Sievers, H.^a | Ganter, M.^b | Jung, F.^c | Hiebl, B.^{a; *}

Affiliations: [a] Institute for Animal Hygiene, Animal Welfare and Farm Animal Behavior, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany | [b] Clinic for Swine and Small Ruminants, Forensic Medicine and Ambulatory Service, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany | [c] Institute of Biotechnology, Molecular Cell Biology, Brandenburg University of Technology Cottbus-Senftenberg, Senftenberg, Germany

Correspondence: [*] Corresponding author: B. Hiebl, Institute for Animal Hygiene, Animal Welfare and Farm Animal Behavior, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany. E-mail: [email protected].

Abstract: 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.

Keywords: Sheep, platelet, activation, platelet volume, CD42a, CD61, CD62P, CD63

DOI: 10.3233/CH-219104

Journal: Clinical Hemorheology and Microcirculation, vol. 79, no. 1, pp. 129-136, 2021