Comparison of IY81149 with omeprazole in rat reflux oesophagitis

1 This study was aimed at evaluating the effects of IY81149{2-[[(4methox)-3 -methyl)-2-pyridinyl]methylsulfinyl]-5-(1H-pyrrol- 2-pyridinyl]methylsulfin yl]-5-(1H-pyrrol-1-yl)-1H-benzimidazole}, a new proton pump inhibitor, on t he development of the surgically induced reflux oesophagitis, on gastric se cretion and on lipid peroxidation which is a marker of oxidative stress. Om eprazole was used as a reference drug. We furthermore investigated the infl uence of quercetin and desferrioxamine (DFO) on the development of the surg ically induced reflux oesophagitis in rats on gastric secretion and on lipi d peroxidation. 2 IY81149 and omeprazole significantly prevented the development of reflux oesophagitis and gastric secretion in a dose-dependent manner. The ED50 val ues of IY81149 for inhibition of oesophagitis and volume of gastric secreti on were lower than of omeprazole (5.7 vs. 14.2 mu mol, 15.3 vs. 24.0 mu mol , respectively). IY81149 was also more potent in the acid output inhibition with an ED50 of 6.8 mu mol compared with 20.8 mu mol of omeprazole. 3 Malonyldialdehyde (MDA) content, the end product of lipid peroxidation, i ncreased significantly in the oesophageal mucosa after the induction of ref lux oesophagitis. IY81149 and omeprazole significantly and dose-dependently prevented lipid peroxidation. Quercetin (200 mg kg(-1), p.o.) and DFO (800 mg kg(-1), i.d.) significantly prevented the development of reflux oesopha gitis and inhibited the lipid peroxidation independent of their actions on gastric secretion. 4 This result suggests that IY81149 is comparable with omeprazole in the tr eatment of reflux oesophagitis.