Efeitos do exercício aeróbio no músculo esquelético de ratos expostos à fumaça de cigarro

Abstract

Introduction: Smokers have reduction in the muscle mass and in the fatigue resistance and, possibly, physical activity practice contributes positively to this state. Objective: This study had as objective to analyze the adaptations of the skeletal musculature to the interaction between physical activity practice and cigarette smoke exposure. Methods: 32 male rats were divided in groups exposed to the cigarette smoke, exercised (G1) and sedentary (G3), and not exposed to cigarette smoke, exercised (G2) and sedentary (G4). The exposure to the smoke was done by the combustion of 10 cigarettes in an inhalation camera during 30 minutes, twice a day, five days per week, during 15 days; the aerobic exercise consisted of daily walking sessions of 60 minutes on treadmill, once a day, five days per week. After sacrifice, soleus muscle was obtained and its cuts were stained by HE technique and submitted to the hystochemical method of NADH-TR. Results: Group G1 presented more muscle alterations, and also lack of enzymatic activity, the same occurring in G3, but with less intensity; G2 presented normal pattern to exercised fibers, being the fibers of G4 preserved. Regarding the morphometry, there was significant difference for the exercise factor (p = 0.007), while no significant differences were observed for the smoke exposure factor (p = 0.668) and for the interaction of exposure to smoke and exercise (p = 0.077). Conclusion: The interaction between cigarette smoke exposure and physical activity during 15 days in male wistar adult rats, accentuated the histological changes in the soleus muscle, causing an alteration in the enzymatic activity and increase in the fiber diameter.