BACKGROUND: Chemokines and their receptors play key roles in the pathogenesis of acute pancreatitis. This study aimed to establish a rat model of severe acute pancreatitis (SAP) for investigating monocyte chemotactic protein-1 (MCP-1) expression in the pathogenesis of the disease. We assessed the effects of the inhibitor of MCP-1, Bindarit, on SAP and explored the mechanisms underlying SAP.
METHODS: Seventy-two Sprague-Dawley rats were randomly divided into a saline control group (group S), an SAP group (group P), and a Bindarit group (group T). The SAP model was induced by retrograde infusion of 4% sodium taurocholate into the biliopancreatic duct. Based on the SAP model, Bindarit was injected intraperitoneally in group T, and 0.5% methyl cellulose was injected intraperitoneally in groups S and P. In group S, saline was retrogradely infused into the bilipancreatic duct. Serum amylase levels and the histological changes in the pancreas were assessed at different time-points in each group. Expression of MCP-1 in serum was measured by enzyme-linked immunoadsorbent assay (ELISA). MCP-1 protein and mRNA expression levels were detected by immunohistochemistry, Western blotting, and semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR).
RESULTS: Serum amylase levels in groups P and T were higher than those in group S. Serum amylase levels were significantly lower in group T than in group P at 6 and 12 hours after operation. The levels of MCP-1 in serum at 6 and 12 hours after operation in group P were significantly higher than in group S, and significantly lower in group T than in group P at 6 and 12 hours after operation. The pathological damage in the pancreas was milder in group T than in group P. MCP-1 protein and mRNA expression levels in the pancreas were higher in groups P and T than in group S. These expression levels were positively correlated with the pathological damage of pancreatic tissues. The activity of MCP-1 in group T was significantly lower than in group P.
CONCLUSION: MCP-1 may play important roles in the pathogenesis of SAP. The data suggest that Bindarit ameliorates SAP by inhibiting the activity of MCP-1 in vivo.