| Objective: Intestinal mucosal barrier dysfunction in severe acute pancreatitis(SAP) prone to intestinal barrier dysfunction. This leads to intestinal bacterial translocation and endotoxemia, induces and aggravates the systemic inflammatory response. Intestinal reactions during and after acute pancreatitis include inflammatory alterations, disturbed motility, stenosis, ulcerations, bleeding, ischemia, necrosis, and perforation. Gastrointestinal complications from pancreatitis have been recognized and can lead to intestinal origin sepsis and even death. So in the treatment of acute pancreatitis, the protection of intestinal mucosal barrier is very important.Neurotensin(NT) can enhance the intestinal mucosal mechanical barrier and capillary permeability. The role of NT in the intestinal barrier dysfunction caused by SAP is unknown.This study was designed to select D-lactate and endotoxin levels as index of intestinal permeability. Application specific NF-κB inhibitor(pyrrolidine dithiocarbamate, PDTC) pretreatment, changes in the small intestine are observed. There are few studies about the Relationship and its mechanism between neurotensin and damage in intestinal mucosa barrier in rats with severe acute pancreatitis.Methods:1 Experimental animal group: 60 adult SD rats were randomly divided into 3 groups: control group, severe acute pancreatitis model group, PDTC intervention group, each group was divided into two subgroups: 12 hours group and 24 hours group, there are 10 rats in each subgroups.2 Experimental models: The rats were given 20% L-arginine(L-Arg) intraperitoneal injection at one-hour interval. In model groups, the rats were given 20% L-Arg intraperitoneal injection by 2.5g/kg,twice at one-hour interval(5.0g/kg rat’s weight)induce SAP. In control groups, the rats received the same amount saline at the same time. In PDTC intervention group, the rat was given PDTC 10mg/kg intraperitoneal injection 1h before the first injection of L-Arg. All rats were killed 12 h or 24 h after the injection of L-Arg to collect blood, pancreas and intestinal tissues.3 Experimental methods: The changes of pancreas and intestinal were observed. The pathologic changes and graded in pancreatic and intestinal tissues were observed. ELISA and Immunohistochemistry were used to detect the expression of NT. We tested the endotoxin and D-lactate in plasma to evaluate intestinal permeability.4 Statistical Methods: Statistical analysis was used by SPSS19.0 for windows. All data were presented as means±SD. The significance was assumed at P<0.05.Results:1 Pancreatic and intestinal histopathology: Model group, pancreas and small intestine inflammation, necrosis, pathological damage extend gradually increasing over time, The changes in 24h’s subgroup were more serious than that at 12 h. The control group had no significant inflammation. Schmidt and Chiu pathology scoring in model group was significantly higher(P <0.01).2 After the pretreatment of PDTC, we found that both rat pancreatic and intestinal tissue pathological score compared with the model group decreased significantly(P<0.01).3 Serum NT: the expression of 12 h and 24 h in NT model group were significantly higher than those in the control group(P<0.01). Compared with the model group, both the 12 h and 24 h expressions were significantly lower in group PDTC(P<0.05). The NT expression of model 24 h group increased significantly than that at 12h(P<0.05).4 Small intestinal tissue NT level: compared with the control group, the expression of NT in model group were significantly higher(P<0.01). PDTC intervention group significantly reduce the expression compared with the model group(P<0.01). There was no significant difference in the expression of NT between 24 h and that at 12 h(P>0.05).5 Small intestinal tissues were detected by NT immunohistochemistry: the expression of NT in model group was significantly higher than those in the control group(P<0.01). The PDTC intervention group compared with the model group, the NT expression was significantly decreased(P<0.01). The NT expression has no obvious change between 12 h and 24 h in all groups(P>0.05).6 Plasma endotoxin: Compared with the control, the concentration of endotoxin in 12 h and 24 h model group were significantly higher(P<0.01), and 24 h is significantly increased than 12h(P<0.05). PDTC group compared with the model group was significantly decreased(P<0.01), but no significant change was found between 12 and 24h(P>0.05).7 plasma D-lactate levels: 1. Compared with the control group, plasma D-lactate in model groups were significantly higher(P<0.01),and plasma D-lactate at 24 h increased significantly than that of 12 h,(P<0.05). Compared with model group, plasma D-lactate in PDTC group was significantly decreased(P<0.01), but no significant change was found between 12 and 24h(P>0.05).8 Small intestinal tissue, blood NT and plasma D- lactate correlation: small intestine tissue, serum NT was positively correlated with plasma D- lactate.Conclusions:1 The expression of NT was higher in SAP rats’ intestinal mucosa, which suggests NT may be adjustment factors in intestinal mucosa barrier2 NF-κB pathway inhibitor PDTC can inhibit the expression of NT.3 The expression of NT may be adjusted partly by the NF-κB pathway. NT may be playing a role in mucosal injury, whether over expression of NT may be aggravated the intestinal mucosal injury which still needs to be further confirmed by experiment. |
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