Platelet covered area (P < 0.01, paired t-test) and average size of platelet covered areas (P < 0.01, paired t-test) of healthy dogs increased significantly after platelet activation with PAR 4 agonist.
Interestingly, platelet activation with PAR 4 agonist still increased average size of platelet covered area.
In vitro addition of LPS or HES significantly reduced platelet covered area after PAR-activation.
Platelet activation with PAR 4 agonist increased average size of platelet covered areas in HES treated samples and in the control, but in comparison to the control average size of platelet covered area in HES treated samples was significantly reduced.
In contrast, in dogs with infection neither platelet covered area nor average size of platelet covered areas increased after platelet activation with PAR 4 agonist (P > 0.05, paired t-test).
In our flow chamber studies, platelet covered area and average size of platelet covered areas in dogs with infection and healthy dogs did not show significant differences at baseline.
Average size of platelet covered areas after activation was significantly lower in comparison to average size of platelet covered areas after activation in the non-treated control (P < 0.05, Mann–Whitney U test).
For flow chamber studies area under the ROC curve was 0.91 for average size of platelet covered area after platelet activation with PAR 4 agonist.
As in the control, platelet activation with PAR 4 agonist in the HES treated samples increased average size of platelet covered areas (P < 0.05, Wilcoxon test).
As in the control, average size of platelet covered areas (P < 0.05, paired t-test) increased significantly after platelet activation with PAR 4 agonist in LPS treated samples.
