Pretreatment with arginine preserves intestinal barrier integrity and reduces bacterial translocation in mice

Abstract 

Objective

To evaluate the effects of arginine on intestinal barrier integrity and bacterial translocation (BT) in mice undergoing intestinal obstruction.

Methods

Mice were divided into 3 groups, treated for 7 d before surgical intervention with isocaloric and isoprotein diets. The ARG group received a diet containing 2% arginine, the IO (intestinal obstruction) and Sham groups, standard chow diet. On the eighth day of treatment, all animals received diethylenetriamine pentaacetic acid (DTPA) solution labeled with ^99mTechnetium (^99mTc-DTPA) by gavage for intestinal permeability analysis. After 90 min, the animals were anesthetized and the terminal ileum ligated. The Sham group only underwent laparotomy. After 4, 8, and 18 h, blood was collected for radioactivity determination. Samples of ileum were collected 18 h after surgery for histological analysis. In another set of animals, BT was evaluated. After 7 d of treatment, all animals received 10⁸ CFU/mL of ^99mTc-E.coli by gavage; 90 min later they were submitted to the surgical procedure described above. BT was determined by the uptake of ^99mTc-E.coli in blood, mesenteric lymph nodes, liver, spleen, and lungs, assessed 18 h after the surgery.

Results

The intestinal permeability and BT were higher in the IO group when compared with the Sham group (P < 0.05). Arginine supplementation reduced intestinal permeability and BT to physiologic levels. Histological analysis showed mucosal ileum preservation in animals treated with arginine.

Conclusion

Arginine was able to preserve barrier integrity, thus reducing BT.

Keywords: Immunonutrition, Arginine, Bacterial translocation, Intestinal barrier