LATE HISTOPATHOLOGIC CHANGES AND HEALING IN AN IMPROVED RODENT MODEL OF ACUTE NECROTIZING PANCREATITIS

Studies of experimental pancreatitis have generally focussed on early time points rather than the stages of healing and resolution or scarri ng. We recently characterized a new pancreatitis model of moderate sev erity by combining intraductal infusion of very low concentrations of glycodeoxycholic acid with intravenous caerulein. This study evaluates late histopathologic changes and gross complications in this pancreat itis model compared to the traditionally used high-dose bile salt mode l in rats. After 14 days, histopathologic features of caerulein pancre atitis were not different from saline controls. High-dose intraductal bile salt infusion resulted in widespread chronic inflammation, acinar dilation and atrophy, marked reactive stromal proliferation, and duct ular budding with periductal fibrosis. In contrast, animals receiving low-dose intraductal bile salt infusion combined with intravenous caer ulein demonstrated a moderate degree of chronic inflammation and acina r atrophy along with an intermediate degree of periductal fibrosis and stromal reaction. We conclude that due to its moderate degree of inju ry, this model may be useful for the study of tissue injury and repair following acute pancreatitis.