ABSTRACT
Omeprazole, a benzimidazole derivative, has proven to be a powerful inhibitor of gastric acid secretion evoked by variety of stimuli. This work was designed to study the effect of different doses of omeprazole [1.8, 3.7 and 7.2 mg/kg] on indomethacin-induced gastric ulcer and on indomethacin-induced changes of gastric acid secretion in male albino rats. Incidence of ulceration, mean ulcer score as well as ulcer and preventive indices were estimated to assess the former, while volume of gastric content, acid out put and acid concentration were estimated to assess the latter. Omeprazole [7.2 mg/kg] was the only dose that could reduce incidence of ulceration. Doses of [3.7 and 7.2 mg/kg] could significantly [P < 0.05] reduce mean acid concentration. However, other mentioned parameters were significantly [P < 0.05] reduced by all used doses in a dose dependant manner. It is obvious that [7.2 mg/kg] is the dose that reduced significantly all measured parameters but the beneficial effect of other doses cannot be discarded