Circulatory mechanisms of gastric mucosal damage and protection.

The history of exploring the circulatory mechanisms underlying chemical injury of the gastric mucosa and protection against such damage is reviewed. Special emphasis is placed on recent findings in the areas of inflammatory mediators and the role of local neuropeptides. Attention is also given to the methods used to assess mucosal blood flow and structural injury in the tissue. After weighing the evidence for and against vascular mechanisms in damage and cytoprotection, it is concluded that the local circulation is involved in both processes, but simple changes in mucosal blood flow or microvascular permeability do not adequately explain the early pathophysiology of injury and protection against damage.