Treatment with a histone deacetylase inhibitor, valproic acid, is associated with increased platelet activation in a large animal model of traumatic brain injury and hemorrhagic shock

Abstract Background We have previously shown that resuscitation with fresh frozen plasma (FFP) in a large animal model of traumatic brain injury (TBI) and hemorrhagic shock (HS) decreases the size of the brain lesion, and that addition of a histone deacetylase inhibitor, valproic acid (VPA), provides synergistic benefits. In this study, we hypothesized that VPA administration would be associated with a conservation of platelet function as measured by increased platelet activation after resuscitation. Materials and methods Ten swine (42-50 kg) were subjected to TBI and HS (40% blood loss). Animals were left in shock for 2 h before resuscitation with either FFP or FFP + VPA (300 mg/kg). Serum levels of platelet activation markers transforming growth factor beta, CD40 L, P-selectin, and platelet endothelial cell adhesion molecule (PECAM) 1 were measured at baseline, postresuscitation, and after a 6-h observation period. Platelet activation markers were also measured in the brain whole cell lysates and immunohistochemistry. Results Circulating P-selectin levels were significantly higher in the FFP + VPA group compared with the FFP alone group (70.85 ± 4.70 versus 48.44 ± 7.28 ng/mL; P