Abstract: Objective To explore the characteristics and role of pancreatic cell apoptosis in the acute phase of sodium taurocholate induced acute pancreatitis. Methods The electron microscopy was used for qualitative detection of apoptosis, terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling （TUNEL） and flow cytometry were employed for quantitative detection of apoptosis. Results In pancreatitis rat model established, pancreatic tissuses were analysed. Electron microscopic detection： In the control group, ultrastructure of pancreatic acinar cells were normal. In the edema group, pathologic findings included formation of autophagic vacuoles and appearance of apoptotic cells and apoptotic bodies. In the necrotizing group, early apoptosis coexisted with necrosis and apoptosis was more significant than in the edematous group. TUNEL detection：At 3 hours, differences between the necrotizing and control groups were highly significant （P＜0.01）, those between the edematous and control groups were significant （P＜0.05）. There were no other significant differences among the groups. But apoptosis was the most significant in the necrotizing group.FCM detection： The results of FCM correlated positively with those of TUNEL. Conclusions Apoptosis is a kind of compensation, able to lighten the severity of the disease, but it can only act positively to a limited extent.

Key words: Acute pancreatitis, Pathology, Apoptosis, Rat