Aggregation of killer whale platelets

An evolutionary history of F12 gene: Emergence, loss, and vulnerability with the environment as a driver

“…Consistent with F12 loss advantages, it has been reported that the generation of N 2 microbubbles may act not only as FXII-activating surfaces in diving activity [129] but can also activate platelets, neutrophils, and complement system in vitro, in vivo, and in humans [130][131][132][133][134][135][136] thereby facilitating the thrombus formation, [8,129,134] coagulopathies [135,137] (Figure 1 and 3), and embolism. [129] Somehow reinforcing the thromboprotective effect of F12 loss in cetaceans, killer whale platelets present in their membrane a lower concentration of arachidonic acid [122,138] than human platelets, [122] and a reduced aggregation ability to several agonist including epinephrine, [138] a blood circulating hormone that significantly increases during diving and whose concentration shows a positive correlation with platelet activation during diving in humans. [139] Moreover, dolphin platelets are significantly bigger than human platelets, [123] a fact that like bird thrombocytes would hinder the formation of resistant arterial thrombus.…”

Flow cytometric kinetic assay of calcium mobilization in whole blood platelets of bottlenose dolphins (Tursiops truncatus)

“…The adaptation of this technique to marine mammals represents a methodological advance for basic and clinical veterinary applications but also for general environmental studies on those species. Indeed, in previous works on dolphins, platelets have been studied mainly from hematological or morphological points of view [35], while in killer whales or elephant seals, platelet activation has been studied by aggregometry, membrane lipid composition or thromboxane production [31,32]. All these experimental procedures require centrifugation, washing or fixation, which impose artifactual conditions to the sample.…”

“…Much like humans and terrestrial mammals, marine mammals may suffer alterations in platelet function and hemostasia due to multiple pathologies, diving disturbances, stress conditions or exposure to environmental contaminants also found in the sea that induce platelet activation [11,[28][29][30]. Such alterations, even when platelet count is normal, can lead to thromboembolic or hemorrhagic disorders [31,32]. Detecting early alterations in platelet function is especially relevant in these species, as they do not show signs of disease until the pathology is already advanced, to minimize signs of weakness that could attract potential predators [33].…”