Efeitos da L-citrulina no processo de translocação bacteriana e na permeabilidade intestinal em modelo experimental de obstrução intestinal

Abstract

L-CITRULLINE EFFECTS ON BACTERIAL TRANSLOCATION ANDINTESTINAL PERMEABILITY IN AN EXPERIMENTAL INTESTINAL OBSTRUCTION MODEL. Citrulline is an amino acid that stands out today as being an important marker of intestinal function, precursor of arginine and regulator of protein metabolism. We evaluated the effects of L-citrulline on bacterial translocation and intestinal permeability.To study bacterial translocation, 24 Swiss male mice were divided randomly into three groups: Sham, IO (intestinal obstruction) and CIT. The CIT group received 30 mg/day of citrulline added to supplemented chow and the other groups fed conventional chow. Both diets were isocaloric and isoproteic. At 8th day, after 7 days of treatment, thegroups received by gavage 108 CFU/mL of 99mTc-E.coli. After 90 min, the animals were anesthetized and underwent surgery (terminal ileum ligation). The Sham group underwent only laparotomy. After 18 h the animals were sacrificed. Blood and organs were removed for radioactivity determination. The intestinal fluid and serum was also collected to measure SIgA and cytokines, respectively by ELISA. To study the intestinal permeability, we used the same treatment and surgery procedure in the experimental groups. After 7 days, the animals received 0.1 mL of 99mTc-DTPA and 90 min later were operated. At 4, 8 and 18 h after this administration the blood was collected for radioactivity determination. Four animals were used to each time investigated. Intestine samples were removed 18 h after surgery for histological analysis. Data were analyzed using Kruskal-Wallis Test and one-way ANOVA, considering p0.05 as significant. The animals of the CIT group showed similar food intake (p>0.05) and less weight gain (p<0.05), concerning to the other groups. The level of bacterial translocation was higher in the IO group (p<0.05). The CIT group reduced bacterial translocation and intestinal permeability, when compared with IO group (p<0.05). Histopathology showed that citrulline may preserve intestinal morphology. The concentration of sIgA in the intestinal fluid was found higher in the group treated with citrulline (p<0.05). IO group showed thehighest levels of IFN- in serum (p<0.05). The levels of IL-10 did not differ between the groups (p>0.05). The results suggest that citrulline reduces bacterial translocation, maintains intestinal permeability, improves local immune response, preserves intestinal integrity and seems to modulate systemic immune response.