Effects of Loud Noise on Oxidation and Lipid peroxidation Variations of Liver Tissue of Rabbit

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Background: In today's world, noise is one of the major physical pollutants. The exact mechanism leading to tissue damage in loud noise is not clear. There are increasing evidences that show damage to cochlear tissue by noise is linked to cell injury induced by free radical species. The aim of this study was to investigate the relationship between change in liver tissue glutathione (anti- oxidant) and malondialdehyde (one metabolite of lipid oxidation) levels that occur in rabbits which were exposed to continuous loud noise.

Materials and Methods: This experimental study was performed on 12 white Newzeland male rabbits in TarbiatModarresUniversity in 2004. The rabbits were assigned to the following two groups: control, and exposed to continuous loud noise for 96 hours (8 h/day for 12 days, SPL=110dBA and 250Hz to 20 KHz). The concentration of malondialdehyde (MDA) and glutathione (GSH) in liver tissue samples were measured in rabbits after exposure to noise. Thiobarbituric acid reacting substance, Ellman's reagent and spectrophotometry techniques were used for this measurement. The data were statically analyzed by SPSS software and 2 groups were compared by t-test. Differences at the level of P<0.05 were considered statistically significant.

Results: Comparison of the biochemical parameters of GSH and MDA measured in treated group with control indicated that antioxidant and lipid peroxidants parameters were suppressed in treated group compared to control group (p<0.05).

Conclusion: Possible similarities between rabbit and human biological system indicate the possible role of noise in causation of oxidative stress in context with liver tissue impairment.