SASAKI, I., KONNO, Y., KAMIYAMA, Y. and SATO, T. Acute Gastric Ulceration in Rats with Obstructive Jaundice with Special Reference to Gastric Mucosal Blood Flow. Tohoku J. exp. Med., 1987, 151(3), 351-358-The mechanism of acute gastric ulceration in rats with obstructive jaundice was investigated in terms of the changes in the gastric mucosal blood flow, and the effect of vagotomy on ulceration was examined. 188 Sprague-Dawley rats weighing about 250g were prepared and divided into 4 groups as follows; control group (sham operation), jaundiced group (ligation of the bile duct), vagotomized group (vagotomy with pyloroplasty), jaundiced and vagotomized group (simultaneous ligation of the bile duct and vagotomy with pyloroplasty). Two weeks after the operation, water immersion and restraint stress procedures were performed in these 4 groups. The gravity of acute gastric ulcerations was calculated by ulcer index. The gastric mucosal blood flow was measured by hydrogen clearance technique. The following results were obtained: In control group, ulcer index was increased and gastric mucosal bloodflow was decreased after the stress procedures. The jaundiced group showed significantly higher ulcer index and early significant decrease of gastric mucosal blood flow after the stress procedures compared to the control group. The vagotomized group showed significantly decreased ulcer index after the stress procedures compared to the control group, however, the gastric mucosal blood flow showed almost the same values as the control group. The jaundiced and vagotomized group showed significant decrease of ulcer index and improvement of decrease of gastric mucosal blood flow compared to the jaundiced group. These results indicated that the gastric mucosal blood flow plays an important role in the occurence of acute gastric ulceration in rats with obstructive jaundice, and vagotomy might be useful to prevent them by maintaining gastric blood flow in obstructive jaundice.