Mesenteric ischemia: a cause of increased gastric blood flow, hyperacidity, and acute gastric ulceration.

1. The effects of acute diminution in superior mesenteric arterial flow on gastric blood flow and acidity were studied in 17 anesthetized dogs. 2. Acute mesenteric ischemia produced a rise in celiac and gastric blood flow, higher total acid concentrations, and increased total acid secretion. Ischemia of 12 hours' duration was associated with gross gastric bleeding and in one animal acute superficial gastric ulcerations. 3. The rise in celiac and gastric blood flow appeared to be a hemodynamic response to the fall in mesenteric arterial pressure and was minimized by ligation of the major artery connecting the mesenteric and celiac vascular beds. 4. The increased acid concentration and secretion appeared to be directly related to, and a result of, the augmented gastric blood flow. 5. A direct causal relationship between mesenteric vascular occlusions and subsequent upper gastrointestinal bleeding is suggested.