Avaliação estereológica dos efeitos do treinamento físico aeróbico moderado na aorta de ratos diabéticos induzidos por estreptozotocina

Abstract

Diabetes mellitus (DM) is a complex chronic metabolic disease that affects millions of people worldwide. It is a multifactorial illness responsible, among other changes, for cardiovascular problems in its patients. Those are the main causes of mortality among them. However, physical exercise has the ability to establish a homeostasis in the body and can prevent these alterations on the patients. Therefore, we analyzed the effects of DM in the rat abdominal aorta structure, as well as the action of moderate aerobic physical exercise as prevention and / or treatment for such macrovascular changes in DM. For this analysis, a globally accepted chemical induction model was used for type I DM, through streptozotocin induction. A three-dimensional morpho-quantitative analysis (stereological design) of the abdominal aorta, based on the Cavalieri principle, was performed along with a volume density analysis of elastic fibers, based on Delesse principle, in 30 male Wistar rats. They were 3 months old and divided in 5 groups (n = 6) (G1- Sedentary control, G2- Sedentary diabetic, G3- Trained control, G4- Trained diabetic and G5- Previously trained diabetic). 3D analysis of the aorta demonstrated that diabetes accounts for a 205% increase in lumen volume, 126% of wall volume and 177% of total abdominal aorta volume, as well as a 126% increase in volume of elastic fibers from the aorta wall. It was also demonstrated that physical exercise is able to reduce 34% in lumen volume level, 37% in wall volume level and 35% in total volume level. The previous physical exercise prevented these changes, providing a 84% reduction on lumen volume, 76% of the volume of the wall and 82% of the total volume, also reducing the volume of the elastic fibers by about 76%. Therefore, it can be concluded that diabetes provides an increase in abdominal aorta volume and the elastic fibers. Besides that, moderate aerobic physical exercise is able to revert and prevent these changes in volume, however, it has shown itself only capable of prevent changes in elastic lamellae.