Specific intraluminal nutrients alter mucosal blood flow during gut ischemia/reperfusion

Background: We have previously demonstrated in a rodent model the differential effects that specific intraluminal nutrients exert on gut ischemia/reperfusion (I/R) injury. Alanine was shown to amplify, whereas glucose protected against, gut I/R injury and associated gut dysfunction. The objective of this study was to determine whether these specific nutrients are associated with alterations in mucosal perfusion during gut I/R. Methods: Sprague-Dawley rats had either a laser doppler probe or a tonometer inserted into a jejunal sac filled with either 10 mmol/L alanine, glucose, or mannitol (osmotic control) followed by 60 minutes of superior mesenteric artery occlusion and 60 minutes of reperfusion. Laser doppler mucosal blood flow and regional P_CO2 (Pr_CO2) measurements were obtained. Results: Mucosal blood flow was significantly increased during both ischemia and reperfusion when intraluminal glucose was present compared with intraluminal alanine. Blood flow changes were reflected by lower jejunal Pr_CO2 measurements with intraluminal glucose compared with intraluminal alanine. Conclusions: Intraluminal glucose can augment mucosal blood flow during gut I/R and may explain the protective effect we previously observed.