Effects of exercise on cardiac oxidative stress in rats after exposure to cigarette smoke

The aim of this study was to evaluate the influence of physical exercise on the levels of oxidative stress in cardiac tissue after the inhalation of cigarette smoke in rats. Rats were divided into four groups: (a) non-smokers + non-exercised (NS+NE); (b) non-smokers + exercised (NS+E); (c) smokers + non-exercised (S+NE); and (d) smokers + exercised (S+E). The cigarette smoke was inhaled during 30 min, twice a day, and then extended to 10 cigarettes for 30 min twice a day. Physical exercise was performed on a treadmill. The initial velocity was 10 m x [min.sup.-1] increasing up to the mark of 30 m x [min.sup.-1]. Cardiac tissue lipoperoxidation (LPO) estimation was performed using the TBARS method. The values were expressed in levels of malondialdehyde (MDA), and enzymatic antioxidant defense was measured by catalase (CAT) activity. These findings indicate that the physical exercise induced lower levels of LPO and increased CAT activity, which attenuated the oxidative stress induced by exposure to cigarette smoke. Key Words: Exercise, Heart, Oxidative Stress, Rats, Smoke