H020920050130 Peer reviewer: Dr. The HAS2 secretory IgA (sIgA) content in the total protein of one milligram of small intestinal mucus was detected using a radioimmunological assay. RESULTS: This research exhibited that LPS-induced DMT1 blocker 2 endotoxemia results in small intestinal mucosa injury. The number of M-cells, DCs, CD8+T cells, and IgA+B cells were decreased while Tr cell and apoptotic lymphocyte figures were increased significantly. The number of CD4+T cells increased DMT1 blocker 2 in the early stages and then slightly decreased by 24 h. The level of IL-4 significantly increased in the early stages and then reversed by the end of the study period. The level of IFN- increased slightly in the early stages and then decreased markedly by the 24 h time point. Level of Foxp3 increased whereas sIgA level decreased. CONCLUSION: Mucosal immune dysfunction forms part of the intestinal barrier injury during endotoxemia. The increased number and function of Tr cells as well as lymphocyte apoptosis result in mucosal immunodeficiency. Keywords:Endotoxemia, Rats, Intestinal mucosa, Immunity == INTRODUCTION == Endotoxemia can induce sepsis which is among the leading causes of death in noncardiac intensive care models (ICUs) in the US, with approximately 750 000 cases and up to 200 000 deaths per 12 months[1]. An epidemiological investigation DMT1 blocker 2 in 3665 ICUs in China showed DMT1 blocker 2 that the overall hospital mortality of severe sepsis is usually 48.7%; the imply hospital cost is usually $11 390 per patient at a imply cost of $502 per patient per day[2]. Despite hospital mortality of 20% for simple sepsis and 40% or higher for severe sepsis or septic shock, there has nonetheless been improvement over the past decade[3]. Lipopolysaccharide (LPS) is usually a component of the outer cell wall of gram-negative bacteria, which gives rise to numerous manifestations of gram-negative endotoxemia and septic shock[4]. Endotoxemia-induced sepsis has been associated with deleterious functional and structural changes in many organs, such as the gastrointestinal tract[5], lungs, and other organs. During sepsis, the most frequent complications within the gastrointestinal tract are mucosal barrier dysfunction and ileus[6]. One of the most important functions of the gastrointestinal tract is the ability to act as a mucosal barrier to infections. Mucosal barrier dysfunction plays an important role in the pathophysiology of sepsis by promoting bacterial stasis, bacterial overgrowth, and bacterial translocation, which can lead to the development of secondary infections and multiple organ failure[7]. Intestinal mucosal barriers consist of a mechanical barrier, a chemical barrier, an immunological barrier, and a biological barrier[8]. Damage to any one of these components causes mucosal barrier dysfunction. The immunological barrier is considered as the first line of defense of the intestinal mucosa from bacterial invasion[9] and plays an important role in the overall defense. It consists of Peyers patches, which are the induction sites of the immune response, and diffused lymphoid tissue which are the effector sites. Intestinal mucosa immune responses rely largely on humoral immunity. The primary functions of the immunological barrier include[10-12] inhibiting bacterial adhesion to the mucosa so that they can be eliminated, neutralizing viruses and toxins, enclosing some antigens of acquired extraneous material to prevent systemic reactions, activating the match 3 (C3) pathway, participating in the anti-infection effect, and protecting probiotics. Therefore, damage to the intestinal immune barrier will result in bacterial translocation and gut-derived endotoxemia. Previous studies have discussed the changes to immunity during sepsis, but what happens to immunity, specifically the gut immunity, during endotoxemia before sepsis is not clear. Thus in the present study, changes to the number and function of intestinal mucosal immune cells in rats with endotoxemia were observed to investigate whether dysfunction of immunological barrier occurred during endotoxemia and to elucidate the potential mechanism of this dysfunction. == MATERIALS AND METHODS == == Animals == Male Wistar rats weighing 200.5 12.3 g were purchased from Vital River Laboratories (Beijing, China). The rats were fed a standard laboratory chow diet (Vital River Laboratories) for 72 h before the experiment and managed at 24 1C, at a relative humidity of 50% 1% with a 12/12-h light/dark cycle. The animals were fasted for 12 h before the experiment, allowing free access to water. All animals were dealt with according to the institutional criteria for the DMT1 blocker 2 care and use of laboratory animals in research. == Methods == Establishment of animal model:A total of 80 animals were included and randomly distributed into the control group (40 rats) and LPS (Escherichia coli, O55: B5, Sigma, St Louis, MO,.