Effects of preadaptation to restricted feeding and cimetidine treatment on gastric mucosal injury and wheel running during exposure to activity-stress

The relationship between gastric injury and wheel running was examined during an activity-stress (A-S) experiment. In Experiment 1, rats were preadapted to a 1-h restricted feeding schedule for either 0, 15, 25 or 35 days prior to entering activity wheels. All rats preadapted to the 1-h feeding schedule had significantly less gastric damage than rats without any preadaptation experience. Survival of A-S was related to the length of preadaptation experience. Regardless of preadaptation experience, rats increased daily running with the greatest increase occurring during the 6-h period preceding the feeding hour. In Experiment 2, rats were injected twice daily with cimetidine (100 mg, ip) or vehicle during the 6-h preceding the feeding session. Rats treated with cimetidine had less mucosal injury but had no increased survival when compared to rats injected with the vehicle. Cimetidine treated rats had essentially the same running pattern as controls. These results demonstrated that the process of mucosal injury did not stimulate excessive wheel running. The data also suggest that mucosal injury is not related to survival in A-S rats.