showed significantly less injury in rats that received ketamine than in rats that did not (2.35 ± 1.14 vs 4.58 ± 0.50, P < 0.0001). The distance traveled by a marker, expressed as percentage of total intestinal length, in rats that received pentobarbital sodium was 20% ± 2% in comparison with 25.9% ± 1.64% in rats that received ketamine (P = 0.017
INTRODUCTIONMesenteric ischemia is a clinical entity with a mortality rate between 60% and 100% that usually requires surgical resection of the necrotic intestinal segment [1] . Although there have been advancements in the treatment of ischemic injury, an ideal treatment has not been defined, and new options should be considered. A promising strategy is the use of anesthetic and sedative agents that might exert protective effects on the injured tissue. Ketamine is an agent that has been recommended for this purpose in clinical situations of sepsis, renal ischemia, cerebral ischemia and serious burn injuries [2][3][4] . The small intestine is very sensitive to ischemic insult [5] . Reperfusion causes additional damage through the release of free radicals, pro-inflammatory cytokines, leukotrienes and other related products [6] . Intestinal Abstract AIM: To investigate the effects of ketamine anesthesia on the motility alterations and tissue injury caused by ischemia/reperfusion in rats. METHODS: T h i r ty m a l e W i s t a r ra t s w e i g h i n g 200-250 g were used. Ischemia was induced by obstructing blood flow in 25% of the total small intestinal length (ileum) with a vascular clamp for 45 min, after which either 60 min or 24 h of reperfusion was allowed. Rats were either anesthetized with pentobarbital sodium (50 mg/kg) or ketamine (100 mg/kg). Control groups received sham surgery. After 60 min of reperfusion, the intestine was examined for morphological alterations, and after 24 h intestinal basic electrical rhythm (BER) frequency was calculated, and intestinal transit determined in all groups. RESULTS: The intestinal mucosa in rats that were anesthetized with ketamine showed moderate alterations such as epithelial lifting, while ulceration and hemorrhage was observed in rats that received pentobarbital sodium after 60 min of reperfusion. Quantitative analysis of structural damage using the Chiu scale