Lipid peroxidation and total radical-trapping potential of the lungs of rats submitted to chronic and sub-chronic stress

Abstract

Exposure to stress induces a cluster of physiological and behavioral changes in an effort to maintain the homeostasis of the organism. Long-term exposure to stress, however, has detrimental effects on several cell functions such as the impairment of antioxidant defenses leading to oxidative damage. Oxidative stress is a central feature of many diseases. The lungs are particularly susceptible to lesions by free radicals and pulmonary antioxidant defenses are extensively distributed and include both enzymatic and non-enzymatic systems. The aim of the present study was to determine lipid peroxidation and total radical-trapping potential (TRAP) changes in lungs of rats submitted to different models of chronic stress. Adult male Wistar rats weighing 180-230 g were submitted to different stressors (variable stress, N = 7) or repeated restraint stress for 15 (N = 10) or 40 days (N = 6) and compared to control groups (N = 10 each). Lipid peroxidation levels were assessed by thiobarbituric acid reactive substances (TBARS), and TRAP was measured by the decrease in luminescence using the 2-2'-azo-bis(2-amidinopropane)-luminol system. Chronic variable stress induced a 51% increase in oxidative stress in lungs (control group: 0.037 ± 0.002; variable stress: 0.056 ± 0.007, P < 0.01). No difference in TBARS was observed after chronic restraint stress, but a significant 57% increase in TRAP was presented by the group repeatedly restrained for 15 days (control group: 2.48 ± 0.42; stressed: 3.65 ± 0.16, P < 0.05). We conclude that different stressors induce different effects on the oxidative status of the organism.

Exercise modulation of total antioxidant capacity (TAC): towards a molecular signature of healthy aging

“…Aging and detraining in rats were associated with reduction of muscle strength as well as TAC, which was partially recovered by resveratrol administration (Kashyap et al 2005). Acute stress causes reduction of TAC but chronic exposure to stress can result in an adaptation characterized by improvement in plasma TAC (Torres et al 2004). Psychological stress reduced plasma levels of TAC, an effect that was partially reverted by an eight week physical exercise program in rats (Rosety-Rodriguez et al 2006).…”

Protection of -tocopherol and selenium against acute effects of malathion on liver and kidney of rats

“…Oxidative stress is also related to xenobiotic exposure and different levels of environmental contamination (Halliwell and Gutteridge, 1999). Peroxidation of membrane lipids seems to be an unavoidable process in tissue injury, which can impair antioxidant defenses, those results in oxidative damage by changing the balance between oxidants and antioxidants (Banerjee et al, 1988;Halliwell and Gutteridge, 1999;Torres et al, 2004).…”

Studies on the protective effects of betaine against oxidative damage during experimentally induced restraint stress in Wistar albino rats

“…Rapid urbanization and the changing social fabric in our society lead to heightened levels of stress both mental and physical. Stress exerts detrimental effects on several cellular functions through impairment of antioxidant defenses, leading to oxidative damage, a process central to many diseases (Torres et al 2004). A substantial literature has focused on anatomical, behavioural, and neuroendocrine changes associated to the exposure to chronic stress.…”