Role of gastric motility in development of stress-induced gastric lesions of rats.

Gastric motility of stressed rats was studied to determine its role in producing stress-induced gastric lesions. Restraint and water immersion resulted in an increase in gastric motility which consisted of an increase in frequency and amplitude of contractions and a rise in gastric tone. This increase reached maximal levels 2 to 4 hr after stress, and persisted thereafter. Formation of gastric lesions was markedly accelerated after occurrence of the increased gastric motility. In contrast, restraint alone neither produced such a vigorous increase in gastric motility, nor were the gastric lesions severe. A continuous infusion of papaverine during restraint and water immersion inhibited increase in frequency and amplitude of gastric contractions and prevented formation of gastric lesions. It is concluded that increased gastric motility is closely associated with marked formation of gastric lesions under conditions of restraint and water immersion stress and is probably a main cause for their vigorous formation, although formation of lesions occurs to a small degree without involvement of gastric motility.