IL33 and acute pancreatitis: Encouraged by our findings in the mouse model, we extended our studies to the non-fatal rat model of pancreatic duct ligation-induced acute pancreatitis.[31], [32] Using ELISA, we detected a greater than 2-fold increase in IL-33 protein concentration in the rat pancreas after 48 hrs of PD, compared to sham controls (Fig. 2B).