[Current concepts in gastric ulcer pathogenesis (author's transl)].

Recent research has opened up new aspects in the pathogenesis of gastric ulcers. The central role of luminal acid remains unchallenged, although hypersecretion of acid is not necessarily a prerequisite factor in acute or chronic ulceration. A delicate balance is now known to exist between several protective mechanisms and this is essential in enabling the gastric mucosa to withstand the high H-ion gradient between lumen and surface cells. Apart from the role played by other protective mechanisms like mucosal permeability, alkaline secretion and secretory status, blood flow and intracellular buffering of influxing H+ seem to be the most important factors in maintaining the integrity of the gastric mucosa, because their absence always leads to ulceration. Chronic ulcer disease may, however, be dependent on a defect in the regeneration of the gastric mucosa, in addition to the lack of one or more protective mechanisms.