Etiopatogenia de la úlcera aguda por estres: rol de los oxidantes derivados del oxígeno / Pathogenesis of gastric stress ulcer: role of oxygen free radicals

We evaluated the role of oxygen free radicals in the induction of acute stress gastric ulcer in rats. After 12 hr of inmobility, ulcers of up to 4 mm were observed in the gastric mucosa. Pretreatment with allopurinol, a xantine oxydase inhibitor, produced a significant reduction in the number and size of lesions (p < 0.0001). No protection was afforded by aluminum hydroxyde or ranitidine alone, but enhanced protection was observed when given in association to allopurinol. A secondary role for H ions is suggested by these findings. Our results support the hypothesis of a role of a oxygen free radicals in the pathogenesis of stress gastric ulcers. Allopurinol might be used in conditions prodisposing to stress in patients