NPR platelets (orange) and PR platelets (blue) have a differential response to thrombin challenge across an endothelial monolayer as measured by ECIS. (A-B) NPR and PR platelet treatment of HUVECs demonstrated a similar dose-response as measured by the AUC of transendothelial electrical resistance. This dose-response curve was preserved in both day 3 (A) and day 7 (B) platelets and there were no significant differences between NPR and PR response for a given concentration. (C-D) NPR platelets were more protective at lower concentrations against thrombin challenge (0.2 U/mL) as measured by AUC of transendothelial electrical resistance on day 3 (C) but this difference was not sustained to day 7 (D). For all studies, samples were performed with 3 to 8 replicates with means and standard deviations of representative samples shown. Analysis was conducted with 2-way ANOVA and the Tukey test post hoc. ∗P < .05. Thr, thrombin.