Endotoxin-induced activation of equine platelets: evidence for direct activation of p38 MAPK pathways and vasoactive mediator production

Abstract

OBJECTIVE AND DESIGN: The aim of this study was to determine the effects of endotoxin on p38 MAPK activation in equine platelets and leukocytes in vivo and in vitro and its role in thromboxane (Tx) production with reference to equine endotoxaemia. METHODS: Six adult Thoroughbred horses were used for in vivo infusion studies and separate in vitro studies. For in vivo studies, following collection of a pre-infusion sample, horses were infused with E. Coli O55:B5 LPS (30 ng/kg; 30 min) during and after which platelets were harvested. For in vitro studies isolated platelets and leukocytes were exposed to LPS (10 pg/ml-1 microg/ml). p38 MAPK activity was assessed by SDS-PAGE followed by immunoblo..