Effects of rivaroxaban and edoxaban on the collagen-induced phosphorylation of HSP27 in human platelets.

PRP was pretreated with various doses of rivaroxaban (A) or edoxaban (B) for 15 min, and then stimulated by 1.0 μg/ml collagen or vehicle for 5 min. The reaction was terminated by the addition of ice-cold EDTA (10 mM) solution. The lysate of platelets was subjected to Western blot analysis using antibodies against phospho-specific HSP27 (Ser-78 and Ser-82), total HSP27 or GAPDH. Representative results of rivaroxaban from ten healthy donors (A) and results of edoxaban from five healthy donors (B) are presented. The histogram shows quantitative representation of the collagen-induced levels obtained from laser densitometric analysis. The phosphorylation levels are expressed as the fold increase to the basal levels presented as lane 1. Each value represents the mean ± SEM. *p<0.05, compared to the value of the vehicle alone, and **p<0.05, compared to the value of collagen alone.