Restraint stress-induced elevation of endogenous glucocorticoids decreases Peyer's patch cell numbers via mechanisms that are either dependent or independent on apoptotic cell death

In this study, we investigated whether restraint stress induces either apoptotic cell death or lymphocyte migration in Peyer's patches. Exposure to stress induced a striking decrease in the number of CD3+CD4+, CD3+CD8+ and B220+ cells. Such decreases were accompanied by the enhanced induction of apoptosis in Peyer's patches. The apoptosis of Peyer's patch cells was completely reversed by pretreatment with either high or low doses of RU-486, a glucocorticoid receptor antagonist. In contrast, the stress-induced lymphopenia was little affected by administration of low doses of RU-486, although such lymphopenia was perfectly inhibited by treatment with high doses of RU-486. Taken together, these results suggest that the stress-induced lymphopenia in Peyer's patches is partly due to apoptotic cell death, although other systems such as lymphocyte migration, may contribute to such a reduction in the number of Peyer's patch cells.