Expressions of Caspase-1 activated cytokines in experimental severe acute pancreatitis.

Objective To study the expressions of Caspase-1 activated cytokines in experimental severe acute pancreatitis(SAP). Methods Thirty-two SD rats were randomized into four groups: healthy controls(HC),SAP 6 h,SAP 12 h and SAP 18 h. SAP was induced by retrograde infusion of 5% sodium taurocholate into the bili-pancreatic duct in SD rats. HC rats underwent identical surgical procedures and duct cannulation without sodium taurocholate infusion. Serum amylase was measured by an automated HITACHI-7150 analyzer. Serum IL-1β protein was measured by ELISA. Myeloperoxidase(MPO) in the pancreas was measured by enzyme chemistry assay. Intrapancreatic expressions of Caspase-1,IL-1β and IL-18 mRNA were detected by semi-quantitative RT-PCR. IL-1β protein expression in pancreatic tissue was detected by immunohistochemistry. Results The serum amylase and IL-1β protein levels were increased significantly ( P 0.01 vs HC),with the increase of intrapancreatic MPO after induction of pancreatitis. Intrapancreatic expression of Caspase-1 was observed readily,but IL-1β and IL-18 mRNA expressions were weak in HC. The expressions of Caspase-1,IL-1β,IL-18 mRNA and IL-1β protein were increased significantly in SAP groups ( P 0.01 vs HC),correlating with the severity of SAP. Conclusions The overexpressions of Caspase-1 activated cytokines IL-1β and IL-18 play a pivotal role in the pathogenesis of SAP.