Abstract

The platelet activity in newborn calves of the Kholmogory breed was assessed. The studies were conducted on 39 animals obtained from healthy cows of 2–3 calving. Calves were examined five times in 2 days during the observation period. A tendency towards an increase in the activity of the aggregation process of blood platelets with all tested inducers was revealed during the neonatal phase. It was noted that the number of discoid platelets in the calf blood tended to decrease during the observation period. In these conditions, the level of activated platelets increased by 12.9% in total and the content of freely circulating aggregates of small, medium, and large sizes increased. These changes were provided in the calves by a slightly increased synthesis of thromboxane in blood platelets, which was due to the increased activity of platelet cyclooxygenase and thromboxane synthetase. In addition, a large role in the increase in platelet activity was played by growth in the quantitative content of adenosine phosphates in platelet granules and some increase in their secretion. The level of actin and myosin in calf discoid platelets during the neonatal phase increased by 6.4 and 12.6%, respectively. This was accompanied by a tendency towards growth in the amount of actin and myosin in platelets during their aggregation in response to a weak and strong inducer by 6.4 and 10.1%, respectively. The calves of the Kholmogory breed are characterized by a slightly increased activity of the hemostatic properties of platelets during the neonatal period, which eliminates their risk of bleeding under optimal conditions for microcirculation. The increasing intravascular platelet activity forms the conditions for optimal anabolic processes in tissues of animals in the neonatal period.

中文翻译：

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Kholmogory品种新生犊牛血小板的生理特性

摘要

评估了Kholmogory品种的新生牛犊中的血小板活性。研究是从39头产犊的2至3头健康母牛身上进行的。在观察期内，在2天内对小牛进行了5次检查。在新生儿期，发现所有受试诱导物的血小板聚集过程活性都有增加的趋势。注意到在观察期间小牛血液中盘状血小板的数量趋于减少。在这些条件下，活化血小板的总量总计增加了12.9％，小，中，大尺寸的自由循环聚集体的含量增加了。这些变化是通过血小板中血栓烷的合成略有增加而在小牛中提供的，这是由于血小板环氧合酶和血栓烷合成酶的活性增加所致。另外，血小板颗粒中磷酸腺苷的定量含量的增加和其分泌的增加在血小板活性的增加中起着重要作用。新生阶段小牛盘状血小板中肌动蛋白和肌球蛋白的水平分别增加了6.4和12.6％。这伴随着血小板聚集过程中肌动蛋白和肌球蛋白含量的增长趋势，分别响应于弱诱导剂和强诱导剂，分别增加了6.4％和10.1％。Kholmogory品种的犊牛的特征是新生儿期血小板止血特性的活性略有增加，从而消除了在微循环最佳条件下出血的风险。