The impact of arginine on bacterial translocation in an intestinal obstruction model in rats

Background & aims: Arginine has been shown to have multiple beneficial metabolic and immunologic effects in stress situations. Supplementation of arginine has been shown to promote wound heating and intestinal mucosal recovery after trauma, ischemia or intestinal resection. Bacterial translocation has also been evaluated although with conflicting results and using different assessing techniques. Therefore, the aim of this study was to evaluate the effects of arginine on bacterial translocation in an intestinal obstruction model in rats using Escherichia coli labeled with (99m)Technetium. Methods: Mate Wistar rats (250-350g) were randomized to receive conventional chow, diet supplemented with pure arginine or diet supplemented with an immunonutrition enteral formula, enriched with arginine, omega-3 fatty acid and RNA. After 7 days, the animals were anesthetized. Terminal iteum was isolated and a ligature was placed around it. E. coli labeled with (99m)Technetium (Tc-99m-E. coli) was inoculated into the intestinal lumen (terminal iteum). After 24 h, the animals were sacrificed. Blood, mesenteric lymph nodes (MLN), liver, spleen and lungs were removed for radioactivity determination. Results: Arginine supplementation (300mg/day, 600mg/day or present in the enteral formula) reduced the level of bacterial translocation when compared with the control group (p<0.05). This was shown by significantly decrease uptake of Tc-99m-E. coli in blood, MLN, liver, spleen and lungs of the animals in the experimental groups (p<0.05). Conclusions: These results have shown that arginine was able to decrease bacteria translocation despite intestinal obstruction. There are several mechanisms which might explain the rote of arginine and these will be the subject of future studies. (c) 2007 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.