Effect of Acute Stress on Immune Cell Counts and the Expression of Tight Junction Proteins in the Duodenal Mucosa of Rats

BACKGROUND/AIMS: Duodenal immune alterations have been reported in a subset of patients with functional dyspepsia (FD). The aim of this study was to investigate the effect of acute stress on immune cell counts and the expression of tight junction proteins in the duodenal mucosa. METHODS: Twenty-one male rats were divided into the following three experimental groups: 1) the nonstressed, control group, 2) the 2-hour-stressed group, and 3) the 4-hour-stressed group. Eosinophils, mast cells and CD4(+) and CD8(+) T lymphocytes in the duodenal mucosa were counted. The protein and mRNA expressions of occludin and zonula occludens-1 (ZO-1) were examined. RESULTS: Eosinophils, mast cells and CD8(+) T lymphocyte counts did not differ between the stressed and control groups. The number of CD4(+) T lymphocytes and the protein and mRNA expressions of occludin and ZO-1 were significantly lower in the 4-hour-stressed group compared with the control group. The plasma adrenocorticotrophic hormone and cortisol levels of the 4-hour-stressed group were significantly higher than those of the control group. CONCLUSIONS: Acute stress reduces the number of CD4(+) T lymphocytes and the expression of tight junction proteins in the duodenal mucosa, which might be associated with the duodenal immune alterations found in a subset of FD patients.