Regulation of mouse pancreatitis-associated protein-I gene expression during caerulein-induced acute pancreatitis

The pancreatitis-associated proteins (PAPs) are major pancreatic secretory proteins during acute pancreatitis. However, mechanisms of regulation of PAP gene expression are poorly understood, and there is a lack of information regarding mouse PAP gene expression. Herein, we employed Northern blotting and RNase protection assays to measure mouse PAP-I mRNA levels in the normal pancreas and intestine, and in the pancreas during caerulein-induced acute pancreatitis. Unexpectedly, we found that mouse PAP-I mRNA levels are constitutively high in the adult pancreas, as well as in the small intestine. Furthermore, mouse pancreatic PAP-I mRNA levels are rapidly and dramatically down-regulated (3 h) after the initiation of caerulein injections, but slowly return to high levels by 72 h. Interestingly, we found that pancreatic PAP-I mRNA levels are also transiently and dramatically down-regulated after L-buthionine-[S,R]-sulfoximine administration. Thus, a correlation between PAP-I mRNA levels and glutathione levels in the mouse pancreas was demonstrated.