EFFECTS OF ESOMEPRAZOLE VERSUS PANTOPRAZOLE IN EXPERIMENTAL ACUTE PANCREATITIS By OSAMA A. MOHAMMED*, AHMED S. DOGHISH**, AHMED I. ABULSOUD** and SAYED A. RAHEEM*** * Pharmacology and Therapeutic Department, Faculty of Medicine, Ain Shams University, Cairo, Egypt ** Biochemistry Department, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt *** Pathology Department, Faculty of Medicine, Al-Azhar University, Cairo, Egypt ABSTRACT Background: Free radicals play a crucial role in acute pancreatitis (AP). Esomeprazole (ESP) is a new member of proton pump inhibitors (PPIs), and it was designed to be more potent than earliest PPIs as pantoprazole (PPZ) for suppressing gastric acid secretion, and both possess an activity towards hydroxyl radical and oxidative stress. Objective: To examine the effect of ESP versus PPZ on the course of experimental AP and on gastric secretory function. Material and Methods: Eighteen adult male guinea pigs were divided into three equal groups: Control, sodium bicarbonate-treated, ESP-treated, and PPZ-treated. Acute pancreatitis was induced by intravenous infusion of caerulein (5 μg/kg/h), followed by determination of gastric secretory function. Severity of AP was examined against control group by histology, enzyme levels (amylase and Iipase) and inflammatory markers (myeloperoxidase "MPO" and lactate dehydrogenase "LDH"). Results: Significant elevation occurred in the pH of gastric secretion in the ESP group in comparison with PPZ and control groups. Histopathological examination showed that edema formation and inflammatory cell infiltration in AP was considerably less after PPZ administration and significantly less after ESP administration. Moreover, lipase, LDH and edema were lower in ESP and PPZ-treated groups in comparison with AP-investigated group indicating less acinar cell leakage with a superior effectiveness of ESP achieved by the significant decrease in edema and MPO in comparison with PPZ Conclusion: Both PPZ and ESP possessed an anti-inflammatory effect based on hydroxyl radical scavenging properties and attenuated the course of experimental AP. However, it was relevant that the protective effectiveness of ESP was more than PPZ as it significantly decreased both LDH and lipase. Therefore, these widely used agents may have a beneficial effect not only in the prevention of gastric ulcer, prophylaxis and treatment of gastroduodenal reflux disease, but also on the clinical course of AP itself. Keywords: Acute pancreatitis, esomeprazole, pantoprazole, oxidative stress