Mechanism of Cell Death in Pancreatitis Induced by Pancreaticobiliary Duct Obstruction in the Rat

Park, Kyung Nam; Rhee, Jong Chul; Lee, Kyu Taek; Kong, Gu

Abstract

BACKGROUND AND AIMS: Mechanism of cell death in human and experimental pancreatitis remain poorly understood. Thus, this study was designed to determine the mechanism of cell death in the model of pancreatitis induced by pancreaticobiliary duct (PBD) ligation in the rat.
METHODS
Thirty five male Sprague-Dawley rats were divided into six groups regarding the duration of PBD obstruction. In each rat, we evaluated the biochemical and morphological changes. Morphological changes were examined by light microscopy. Chromatin condensation and DNA breaks were assessed using Apoptag In Situ Apoptosis Detection Kit.
RESULTS
The level of amylase and lipase peaked within 24 hours after PBD obstruction, and returned to baseline after 5 days despite persistent obstruction. Acinar cell deletion and proliferation of ductal-like cells were prominent 3 days after PBD obstruction without an acute inflammatory response. There was no evidence of acinar cell necrosis after PBD obstruction. Complete deletion of acinar cells and severe atrophic changes of pancreas with fibrosis were observed 7 days after PBD obstruction. Apoptosis reached peak level on the third day after PBD obstruction and then declined.
CONCLUSIONS
Apoptosis was the major meehanism of cell death after pan- creaticobiliary duct obstruction in the rat.