Abstract
AIM:To undergo apoptosis during negative and positive selection processes in rat mucosal immune system which are implicated in the pathogenesis of various mucosal diseases.METHODS: Female Sprague-Dawley rats were given protein synthesis inhibitor, cycloheximide, intravenously or intraperitoneally, an apoptosis was recognized by morphological hallmark under light and electronmicroscopy, and the expression of proliferating cell nuclear antigen was visualized immunohisto-chemically.RESULTS: The apoptosis of mucosal lymphocytes in the digestive tract, as well as in trachea, uterus and lacrimal gland was induced by cycloheximide (>1.0mg·kg(-1) body weight), which were located mainly in lamina propria and germinal centers of lymphoid nodules. At the same time, a portion of crypt epithelial cells of proliferating zone in small and large intestine, and the epithelial cells in genital tract were also found to undergo apoptosis. Immunostainings showed that apoptotic cells expressed proliferating cell nuclearantigen.CONCLUSION: Apo-ptosis of lymphocytes in mucosal immune system can be induced by cycloheximide. This model will facilitate the understanding of normal mucosal immune system and its role in the pathogenesis of related diseases such as inflammatory bowel diseases.