Comparison of the response using ICR mice derived from three different sources to ethanol/hydrochloric acid-induced gastric injury

Animal models for gastric ulcers produced by physical, pharmacological and surgical methods have been widely employed to evaluate therapeutic drugs and investigate the mechanism of action of this disease. ICR mice were selected to produce this model, even though several mice and rats have been widely used in studies of gastric ulcers. To compare the responses of ICR mice obtained from three different sources to gastric ulcer inducers, alterations in gastric injury, histopathological structure, and inflammation were measured in Korl:ICR (Korea NIFDS source), A:ICR (USA source) and B:ICR (Japan source) treated with three concentrations of ethanol (EtOH) (50, 70, and 90%) in 150 mM hydrochloric acid (HCl) solution. Firstly, the stomach lesion index gradually increased as the EtOH concentration increased in three ICR groups. Moreover, a significant increase in the level of mucosal injury, edema and the number of inflammatory cells was similarly detected in the EtOH/HCl treated group compared with the vehicle treated group in three ICR groups. Furthermore, the number of infiltrated mast cells and IL-1β expression were very similar in the ICR group derived from three different sources, although some differences in IL-1β expression were detected. Especially, the level of IL-1β mRNA in 50 and 90EtOH/HCl treated group was higher in Korl:ICR and A:ICR than B:ICR. Overall, the results of this study suggest that Korl:ICR, A:ICR and B:ICR derived from different sources have an overall similar response to gastric ulcer induced by EtOH/HCl administration, although there were some differences in the magnitude of their responses.