Age differences and stress ulcer in the rat.

Rats 2-, 7- and 12-mo. old were exposed to supine body restraint plus cold (5 degrees C) for 3 hr. The mean cumulative length of lesions for the 2-, 7-, and 12 mo. old rats was 22.0, 43.0 and 16.0 mm. respectively. The same experimental design was used in a second study, but the pylorus was ligated prior to restraint. Total acid output/hr. was 134.6, 178.2, and 64.7 muEq/60 min. respectively for the three age groups. Older rats were not more susceptible to stress-ulcer and gastric acid was not significantly related to degree of ulceration.