Effects of manipulating cholinergic tone upon the activity-stress ulcer.

Eighty rats were housed in standard activity wheel cages and fed for only 1 hr per day. The animals were divided into 10-animal drug groups that received either 0.25, 050, 1.0 mg/kg of scopolamine methylbromide, or 0.06, 0.125, 0.250 mg/kg of carbachol, 3 times a day. Two separate 10-animal saline control groups accompaned each drug series. All animals died within 6 days and most demonstrated significant gastric lesions in the glandular fundus of the stomach. All dosages of scopolamine methylbromide significantly reduced the number and severity of gastric lesions and in some cases abolished all signs of stomach pathology. None of the dosages of carbachol significantly affected either the number of degree of gastric ulceration noted in the body of the stomach. These results were interpreted to suggest that the secretion of gastric acid may be an important contributing factor in the formation of gastric ulcers in animals subjected to the activity-stress procedure.