Age related changes in the small intestine

In our study, we examined the relation between the length of villi, thickness of tunica muscularis, number of goblet cells and duodenal glands in the rat duodenum in the periods of postpartum days 1 and 22, week 10, and months 8 and 22 using Alcian blue - PAS staining method. In addition, we aimed at determining the possible location of leptin and leptin receptors according to age using immunohistochemical methods.It was found with histochemical staining that length of villi increased with age, Lieberkühn glands grew deeper, goblet cells grew in the basal of the glands in the epithelium, connective tissue of the villi increased with the increasing age, infiltration of single-nucleus cells increased in the connective tissue of the villi, muscle layer and submucosa thickened, and Brunner glands became fully active starting from puberty. While such increases were significant in the period between days 1 and 22, no significant differences were observed in other groups starting from adolescents.We found in the immunohistochemical examinations performed using leptin antibody in age groups starting with the neonatal period and increasing thereafter that strong holding of leptin in the superficial epithelium and villi was observed while this characteristic diminished towards adulthood, and then in increased again and spread in the cytoplasm. We observed that horizontal fibers did not display any immunereactivity; however, longitudinal fibers displayed immunereactivity.In the immunohistochemical staining performed using leptin receptor antibody, it was seen that holding decreased with increasing age, and was in the levels of apical cytoplasmic and membrane of the epithelium.As a result of our study, it was concluded that the holding of leptin within the periods we examined could result from individual differences and eating habits. It was seen that leptin receptor holding decreased with the increasing age; and it was thought that this situation can be connected with a mechanism which could be orrientated to prevent extreme answer that could be seem because of leptin activation.