Microvascular changes of gastric mucosa in the development of stress ulcer in rats.

Abstract

Gastric mucosal microvascular patterns were studied in normal and rotationally stressed rats by India ink injection and silicone rubber perfusion techniques. In normal rats, the mucosal microvascular pattern is characterized by a capillary network which encloses the gastric glands and spans the distance between the connecting arterioles at the base of the mucosa and the tips of the connecting venules at the surface of the mucosa. Submucosal arteriovenous anastomoses, from 20 μ to 40 μ in size, are demonstrated. In the stressed rats, ischemic change of the mucosa, which is initially general but becomes focal later, is a consistent finding. The results of this study indicate that, in stress, mucosal ischemia is caused by contraction of connecting arterioles, and that persistent, focal ischemia of the gastric mucosa triggers tissue damage and development of stress ulcer.