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

• Published in: Brazilian journal of medical and biological research Vol. 37; no. 2; pp. 185 - 192
• Main Authors: Torres, R L, Torres, I L S, Gamaro, G D, Fontella, F U, Silveira, P P, Moreira, J S R, Lacerda, M, Amoretti, J R, Rech, D, Dalmaz, C, Belló, A A
• Format: Journal Article
• Language: English; Portuguese
• Published: Brazil Associação Brasileira de Divulgação Científica 01.02.2004
• Subjects: Animals; BIOLOGY; Disease Models, Animal; Free radicals; Free Radicals - metabolism; Lipid Peroxidation; Lung - metabolism; Lungs; Male; MEDICINE, RESEARCH & EXPERIMENTAL; Oxidative Stress; Rats; Rats, Wistar; Restraint, Physical; Stress; Stress, Physiological - metabolism; TBARS; Thiobarbituric Acid Reactive Substances - metabolism; TRAP; Oxidative stress; TBARS; TRAP; Free radicals; Lungs; Stress
• ISSN: 0100-879X; 1414-431X; 0100-879X; 0034-7310
• DOI: 10.1590/S0100-879X2004000200004

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.