These studies were performed to characterize the pattern of gastric contractility associated with cold restraint-induced lesion formation. Gastric motility in the rat was examined with extraluminal transducers at three sites of the stomach. The motility was monitored in the 24-h-fasted state, the postprandial state, and during cold-water immersion restraint. Gastric acid secretion was also monitored in a separate group of animals placed in cold restraint. Both feeding and cold restraint resulted in an equivalent increase in the amplitude of gastric contractions. Prolonged cold restraint, however, resulted in a distinct contractile pattern in which contractions were 56% less frequent and 300-400% longer in duration than those stimulated by feeding. All cold-restrained animals developed multiple gastric erosions. Cold restraint was not associated with increased acid secretion. A single subcutaneous injection of papaverine HCl (50 or 100 mg/kg) suppressed cold restraint-induced high-amplitude contractions and the cold restraint-induced lesion formation without altering acid secretion. These studies suggest that the stimulation of high-amplitude, prolonged duration contractions are more important than changes in gastric acid secretion in the formation of cold restraint-induced gastric lesions.
