Lack of enteral feeding increases expression of E-selectin after LPS challenge

Background. Total parenteral nutrition (IV-TPN) increases neutrophil accumu lation in the small intestine, expression of intestinal ICAM-1 and P-select in, and upregulates E-selectin expression in the lung. Endothelial activati on induced by lack of enteral nutrition may change the response to injury o r infection. This study investigated whether nutrition influenced the expre ssion of the adhesion molecule, E-selectin and ICAM-1, following endotoxin challenge. Materials and methods. Forty-three mice were injected with saline, 2, 20, 2 00, 2000, or 10000 mug/kg lipopolysaccharide (LPS) intraperitoneally. E-sel ectin expression in the lung, small intestine, and heart was quantified at 3 h after challenge, while ICAM-1 was measured at 5 h, using the dual-radio labeled monoclonal antibody technique. Next, 80 mice were fed chow, intraga stric (IG)-TPN, or IV-TPN for 5 days, and then received intraperitoneal 2 o r 200 mug/kg LPS, E-selectin and ICAM-1 expression in organs was measured a t 3 and 5 h after endotoxin, respectively. Results. E-selectin expression in organs increased LPS dose dependently. IC AM-1 levels reached early peaks in the lung and in the intestine. Also, IV- TPN significantly increased E-selectin expression in the small intestine an d tended to increase pulmonary E-selectin, when compared to chow or IG-TPN animals. There were no significant differences in E-selectin expression amo ng three diet groups after 200 mug/kg LPS challenge. No differences in ICAM -1 expression were observed in any organ among the three groups after 2 or 200 mug/kg LPS injection. Conclusions. E-selectin rather than ICAM-1, because of the expression patte rn after various dosages of LPS challenge, may be a determining factor for the degree of LPS-induced inflammation at the early phase. Lack of enteral nutrition may increase inflammatory response through enhanced gut E-selecti n levels after a Small dose of LPS. (C) 2001 Academic Press.