Ulcers produced by ligation of individual gastric mucosal arteries in the guinea pig.

It is not known whether or not individual gastric mucosal arteries are end-arteries. We therefore occluded single mucosal guinea pig arteries, resulting in necrosis of the whole thickness of mucosa in the area supplied by the artery in 25 of 33 cases (76%). However, there were no cases of necrosis in 33 control sham ligations performed in the same animals (p less than 0.001). In another group, ligation of two or three adjacent mucosal arteries resulted in necrosis in 10 of 11 cases (p less than 0.0001), against 0 necrosis in 11 sham ligations. Killing the animals at varying intervals showed that after 1 day the mucosa was necrotic, after 2 days it was shed, and later it might perforate. We conclude that many mucosal arteries in the guinea pig may behave as functional end-arteries. How these findings may pertain to ulceration is discussed in relation to (a) the existence of atypical mucosal arteries found in the ulcer-bearing areas in humans and (b) the role of the muscularis mucosae on arterioles perforating it in both humans and other species.