The protective effect of a novel synthetic zinc-carnosine chelate compound, zinc N-(3-aminopropionyl)-L-histidine (Z-103), on the gastric mucosal injury induced by ischemia-reperfusion was studied in rats. Ischemia and reperfusion injury was produced on the rat stomach by applying a small clamp to the celiac artery for 30 min and by removal of the clamp for 30 min. The decrease in the gastric mucosal blood flow was not influenced by the treatment with Z-103. The increase in total area of the erosions on the stomach after ischemia-reperfusion and the increase in lipid peroxides in the gastric mucosa were significantly inhibited by the oral administration of Z-103. In addition, Z-103 inhibited lipid peroxidation of rat brain homogenate and liver microsome in vitro. These results suggest that the protective effect of Z-103 against the aggravation of gastric mucosal injury induced by ischemia-reperfusion may be due to its inhibitory effect on lipid peroxidation.