Gut neuroendocrine cells: relationship to the proliferative activity and apoptosis of mucous epitheliocytes in aging.
OBJECTIVES: Diffuse neuroendocrine system (DNES) cells regulate homeostasis via neurocrine, endocrine and paracrine mechanisms. Extensive effects of peptide hormones and biogenic amines necessitate studying of DNES cell biology in aging. In this connection, the functional morphology of gut neuroendocrine cells (NEC), proliferative activity and apoptosis of mucous epithelial cells in aging have been studied.
MATERIAL AND METHODS: The study was performed on BALB/c-nu mice of 4, 21 and 34 months of age. NEC, proliferative activity and apoptosis of mucous epitheliocytes in stomach and duodenum have been studied by histochemical, immunohistochemical and morphometrical methods.
RESULTS: The total number of NEC shows an increasing trend with advancing age. However, the different types of NEC elicit differential patterns. The total number of epithelial cell nuclei does not show any statistically significant difference during aging. The proliferative activity of mucous epitheliocytes also shows no difference among the three animal groups studied. On the contrary, the apoptotic index increases with advancing age.
CONCLUSIONS: The results demonstrate that various gut NEC show differential behavior with age and their time-courses are dependent on the site of location (stomach or duodenum). The picture seems quite complex to allow a comprehensive interpretation, nonetheless it gives us some useful indications for further investigation. In fact, since the gut does not show evident gross age-related physiological changes, modifications with age in specific biological parameters can suggest the key mechanisms of compensative regulatory processes possibly acting during aging....