Oxidative stress in the heart of rats exposed to acute intermittent hypobaric hypoxia

It is known that the altitude area causes hypoxic conditions due to the low oxygen partial pressure. This study was conducted to estimate oxidative stress indices in the heart tissue after Wister rats exposure to the acute intermittent hypobaric hypoxia. Hypobaric hypoxia exposure was simulated by keeping the rats in a hypobaric chamber for 1 min at 35,000 feet altitude. After that the altitude was gradually reduced to 30,000 and 25,000 feet and maitained for 5 min. 25 male Wistar rats were divided into control group and four treatment groups (I-IV), consisting of rats exposed 1, 2, 3 and 4 times to hypobaric hypoxia with a frequency once a week. The animals were removed from the experiment at the height of 18,000 feet and the heart tissue was obtained. The carbonyl groups and MDA levels and superoxide dismutase and catalase activity were exami­ned in the supernatant of the heart tissue homogenate. In the samples of group I, the decrease in catalase activity with a simultaneous notable increase in carbonyl groups level was observed compared to control. In the samples of groups III and IV, the carbonyl level normalized and the activity of both antioxidant enzymes increased significantly. It was concluded that the increase of antioxidant enzymes activity can contribute to cardiac tissue adaptive response to acute hypobaric hypoxia exposure.