Characteristics of the intestinal epithelial barrier during dietary manipulation and glucocorticoid stress.

Objectives: a) To determine the significance of stress-induced alterations in intestinal permeability by measuring the transmucosal flux of formyl-methionyl-leucyl-phenylalanine (f-MLP), a ubiquitous neutrophilic chemoattractant present in the human and rodent colon; and b) to determine whether stress and/or diet influence(s) bacterial adherence-induced changes in epithelial permeability by affecting the production of secretory immunoglobulin A (IgA), the main immune mechanism preventing bacterial adherence.

Design: Prospective, randomized, controlled study.

Setting: University animal research laboratory.

The effect of dexamethasone administration on rat intestinal permeability: the role of bacterial adherence.

Background/aims: Previous studies have shown that dexamethasone administration to rats results in diminution of biliary secretory immunoglobulin A concentration and alters intestinal barrier function to bacteria. The aims of this study were to examine and characterize the effect of dexamethasone on intestinal permeability and to determine the possible influence of bacterial adherence to the mucosa in this process.

Methods: Groups of adult Fisher rats were studied, and the effects of dexamethasone administration and bowel decontamination on bacterial adherence and intestinal permeability were determined in various bowel segments.

The effect of dexamethasone and endotoxin administration on biliary IgA and bacterial adherence.

Adherence of bacteria to the intestinal epithelial cell may be the crucial initiating event for invasion and translocation and is normally prevented by both immune (IgA) and nonimmune (mucus, peristalsis, desquamation) mucosal defense mechanisms. The purpose of the present study was to examine the effect of endotoxin administration on mucosal immunity and to define the role of glucocorticoids, commonly released during endotoxicosis, in this process. Thirty female Fisher rats were randomly assigned to three groups of 10 animals each.

The effect of glutamine-enriched TPN on gut immune cellularity.

Prolonged parenteral feeding with standard nutrient solutions results in significant alteration in the structural, hormonal, and immunological composition of the intestinal tract. The purpose of the following study was to evaluate the effect of glutamine-supplemented parenteral nutrition on the immune cellularity of the gut. Twenty-one Fischer rats were randomized to three groups of seven animals each.

The effect of glucocorticoid administration on bacterial translocation. Evidence for an acquired mucosal immunodeficient state.

Adherence of bacteria to intestinal epithelial cells may be the crucial initiating event for translocation and is normally prevented by both specific (secretory IgA) and nonspecific (mucus, bacterial antagonism, desquamation) mucosal defense mechanisms. The purpose of this study was to examine the effect of dexamethasone administration on mucosal immunity; specifically bacterial adherence and IgA. Twenty Fischer rats were randomly assigned to two groups of 10 animals each.