آثار صداي شديد با فركانس هاي زير و بم در افت شنوايي و سيستم اكسيداتيو استرس خون و كبد خرگوش

Effects of Noise Intense in Different Frequencies (high and low) on Noise Induced Hearing loss and Oxidative Stress in Blood and Liver of Rabbits

Noise-related hearing impairment has been diagnosed since the beginning of written history and studies have begun to find ways of protecting from noise and providing suitable treatment. This study was performed to investigate the relationship between noise-related hearing impairment of rabbit being exposed to continuous noise and its relation to glutathione (GSH) and malondialdehyde (MDA) formation in liver and blood. Animals well randomly divided into four groups: Groups 1, 2 and 3 exposed to continuous noise (8 h/day for 96 hours) respectively (SPL=110dBA, 250Hz to 20KHz), (SPL=110dBA, 250Hz to 3540Hz) and group 4 (SPL=110dBA, 3540Hz to 20KHz) and group 4 (Control) Pre-exposure and after the noise ended, animals were anaesthetized. Then auditory Brain Stem response (ABR) and Distortion Product Otoacoustic Emission (DPOAE) measurement were performed in animals before and after exposure to noise. Following audiometery, venous blood was obtained into tubes with heparin. Then rabbits were decapitated, liver samples were collected and used to measure levels of MDA and GSH in blood and liver samples. Comparisons among groups were used by one-way variance analysis (ANOVA). Differences at the level of P<0.05 were- considered statistically significant. Comparison of the auditory and biochemical parameters measured in treated groups with reduction in hearing threshold respecting control showed significant (P<0.05). This was associated with alternating in the balance of preoxidant and antioxidant parameters.