RESUMO
AIM: We aimed to evaluate whether the streptozotocin-induced diabetic model can generate lung functional, histological and biochemical impairments and whether moderate exercise can prevent these changes. METHODS: Wistar rats were assigned to control (CTRL), exercise (EXE), diabetic (D) and diabetic with exercise (D+EXE) groups. We used the n5-STZ model of diabetes mellitus triggered by a single injection of streptozotocin (STZ, 120 mg/kg b.w., i.p.) in newborn rats on their 5th day of life. EXE and D+EXE rats were trained by running on a motorized treadmill, 5 days a week for 9 weeks. Blood glucose, body weight, food intake, exercise capacity, lung mechanics, morphology, and antioxidant enzymatic activity were analysed. RESULTS: On the 14th week of life, diabetic rats exhibited a significant impairment in post-prandial glycaemia, glucose tolerance, body weight, food intake, lung function (tissue viscance, elastance, Newtonian resistance and hysteresis), morphological parameters, redox balance and exercise capacity. Physical training completely prevented the diabetes-induced alterations, except for those on fasting blood glucose, which nevertheless remained stable. CONCLUSIONS: Mild diabetes in n5-STZ-treated rats jeopardized pulmonary mechanics, morphology and redox balance, which confirms the occurrence of diabetes-induced pneumopathy. Moreover, moderate exercise completely prevented all diabetes-induced respiratory alterations.
