FASTING-INDUCED REDUCTION OF INTESTINAL REPERFUSION INJURY

Background: Fasting is associated with significant structural, functio nal, and metabolic alterations in the intestinal mucosa Before abdomin al surgery, patients are usually fasted the night before surgery or fo r a longer period of time if chronic illness is present. The splanchni c organs may experience varying degrees of ischemia/reperfusion as blo od vessels are occluded during the various manipulations. Methods: To study whether fasting alters intestinal reperfusion injury, rats were fasted for 0 to 2 days, and the mesenteric artery was occluded for 30 minutes and then reperfused for 1 hour. Mucosal atrophy was quantitate d by measuring jejunal villus height and crypt depth, and mucosal inju ry was quantitated by measuring jejunal villus width to villus height and mucosal integrity. To determine whether any effect of fasting on r eperfusion injury was due to the absence of luminal nutrients or to a systemic nutrient deficiency, rats were fed parenterally for 7 days be fore ischemia/reperfusion. Results. A 1-day fast produced significant mucosal atrophy. Reperfusion in the 0-day and 1-day fasted animals pro duced mucosal injury and additional mucosal atrophy. After a 2-day fas t, there was no mucosal injury or mucosal atrophy other than that prod uced by fasting alone. Parenteral feeding before ischemia/reperfusion did not prevent ischemia/reperfusion induced mucosal atrophy and injur y. Conclusions: The protective effect of a 2-day fast before intestina l ischemia/reperfusion cannot be attributed to the physical and chemic al absence of food within the intestinal lumen.