The proposed research is designed to provide new information about the flow of blood within the smallest blood vessels of the stomach in order to better understand the relationship between blood flow and acid secretion, as well as the cause of one type of stomach ulcer (stress ulcer). This work employs direct observations of the microcirculation of the living stomach in anesthetized animals. A TV microscope system will be used to view and record changes in vessel diameter, flow rate, and reaction to various physiologic and pathologic stimuli. BIBLIOGRAPHIC REFERENCE: Goldstone J, Patel MD, Way LW: Effect of Gastric Acid Inhibition by Metiamide and Vagotomy upon Mucosal Microcirculation. Gastroenterology 72:1064, 1977 (abstract).