Abstract: Objective: To investigate the influence of spleen on the production and release of inflammatory mediator in acute pancreatitis.Methods: Acute necrotizing pancreatitis(ANP) was induced in SD rats by injecting 3% sodium taurocholate and trypsin into the biliopancreatic duct.All rats were divided into four groups randomly:sham operation group,splenectomy group,acute pareatitis with splenectomy group,and acute pancreatitis group.The serum levels of TNF-α,IL-1β,IL-6 and IL-10 in each group were examined.The terminal ileum was excised to observe the injury of intestinal mucosal barrier by optical microscope and electronic microscope.Results: The serum levels of TNF-α,IL-1β and IL-10 in the acute pareatitis with splenectomy group were significantly lower than those in the acute pancreatitis group(P<0.01).Histological examination revealed mild edema of mucosal epithelium and normally appearing intact mucosal barrier in the acute pareatitis with splenectomy group,whereas acute pancreatitis group revealed severe injuries including apparent edema,necrosis of the intestinal villi,degeneration of epithelial cell and infiltration of neutrophils.Conclusions: Spleen may promote the production and release of inflammatory mediators in acute inflammatory response,and aggravate the inflammatory response.Splenectomy can reduce the production and release of inflammatory mediators,thus decrease the damage of intestinal mucosal barrier.