Ultrastructural alterations in colon absorptive cells of alloxan-induced diabetic rats submitted to long-term physical training.

Absorptive cells have notable importance for proper function of the colon, absorbing water and nutrients. In type I diabetes, hyperglycemia leads to remarkable alterations in cell structure. In absorptive cells, such changes may impair the function of the organ as a whole. Also, the effects of physical training, which plays crucial role in the treatment of diabetes, are not yet known in these cells. For this reason, to analyze the changes in colon epithelial absorptive cells of diabetic rats and the effects of physical training, Wistar rats were divided into four groups: sedentary control (SC), trained control (TC), sedentary diabetic (SD), and trained diabetic (TD). The training protocol consisted of swimming for 60 min a day, 5 days per week, during 8 weeks. Colon samples were collected, processed, and evaluated by histochemical and ultrastructural techniques. Although histochemical analysis did not reveal major differences, significant morphological differences were ultrastructurally observed among groups, especially related to the structure of tight junctions, interdigitations, and microvilli, which became longer in diabetics, and whose length was reduced after physical training, as proved by statistical analysis. There were no relevant changes in organelles. Thus, the development of type I diabetes can lead to changes at ultrastructural level that, even subtle, may cause important alterations in cell function. The practice of physical training, in turn, proved to be an important ally in the treatment of such changes. However, it cannot be used singly for treating this disease, requiring the combined practice of other methods.