GASTRIC CONTRACTIONS, SECRETIONS AND INJURY IN COLD RESTRAINT

The clinical syndrome of stress ulceration has been studied for years using rodent cold restraint stress models, although the pathogenesis o f the characteristic focal gastric mucosal lesions produced in these m odels has been controversial We used gastric strain gauges to characte rize fully the gastric motility effects of a 4-h cold restraint protoc ol, and we determined the relationship of variations in gastric conten ts and in gastric contractions to the amount of gastric mucosal injury . Additionally, we examined rat stomachs histologically, and determine d the location of focal haemorrhagic mucosal lesions on the mucosal ru gae. We found a consistent relationship between force of gastric contr actions and gastric mucosal injury and also a relationship, between th e initial duration of contractions during restraint and ultimate mucos al injury. Volume, acidity and mucus in the gastric contents were unre lated to mucosal injury. The majority (91%) of the mucosal lesions had some relationship to a rugal fold, with 59% of all lesions at the bas e of a rugal fold. Thus, the mechanical forces of gastric hypercontrac tility may contribute to the gastric mucosal injury of rodent cold res traint models.