We evaluated the effects of acute high-dose sodium selenite (SEL) administration on the intestinal microcirculation and the release of the cytokines TNF-alpha, IL-1beta, IL-6 and IL-10 in experimental endotoxemia (induced by lipopolysaccharide-LPS). Three groups of animals (n=30) were studied: control group, endotoxemic group (15 mg kg(-1) i.v. LPS from E. coli) and SEL-treated LPS group (100 microg kg(-1) SEL i.v.). SEL treatment resulted in a significant reduced number of firmly adhering leukocytes in intestinal submucosal venules and reduced significantly the impairment of the intestinal functional capillary density. Despite of the improvement of microcirculatory parameters, we did not detect any changes in the pattern of cytokine release. In conclusion, administration of high-dose sodium SEL attenuates leukocyte adhesion and improves capillary perfusion within the intestinal microcirculation without affecting release of the cytokines TNF-alpha, IL-1beta, IL-6 and IL-10 in experimental endotoxemia.