Abstract: Objective  To explore the effects of ethyl pyruvate (EP) on the small intestine barrier in rats with sepsis and its possible mechanism. Methods  A total of 85 Wistar rats with sepsis induced by cecal ligation and puncture surgery (CLP) were randomly divided into 3 groups: Ringers administration group (Rin group), the septic group with ethyl pyruvate administration (EP group) and sham-operated group(the control group). The histological changes and bacterial translocation in the ileal architecture microvascular were observed, perfusion of small intestine, activity of myeloperoxidase (MPO), the level of inducible nitric oxide synthase (iNOS) mRNA and rat mast cell protease-Ⅱ (RMCP Ⅱ) were tested, and the survival rate of rats was calculated. Results  The Rin group had more severe injury of small intestinal mucosa, while the EP group had better morphological changes, and fewer bacterial colonies shift compared with the Rin group. Compared with the control group, the Rin group had weaker blood flow, higher expression of MPO, RMCP Ⅱ, and iNOS (all P<0.001). Compared with the Rin group, EP group had enlarged blood flow, decreased expressions of MPO and iNOS, and higher survival rate of animals (all P<0.001). Conclusion  EP can ameliorate the morality rate of sepsis and improve the microcirculation by decreasing MPO and iNOS expressions in the small intestine, which may protect the small intestine barrier of septic rats.

Key words: Ethyl pyruvate, Wistar, Rats, Small intestine barrier, Sepsis