Leupeptin reduces impulse noise induced hearing loss
BACKGROUND Exposure to continuous and impulse noise can induce a hearing loss. Leupeptin is an inhibitor of the calpains, a family of calcium-activated proteases which promote cell death. The objective of this study is to assess whether Leupeptin could reduce the hearing loss resulting from rifle impulse noise. METHODS A polyethelene tube was implanted into middle ear cavities of eight fat sand rats (16 ears). Following determination of auditory nerve brainstem evoked response (ABR) threshold in each ear, the animals were exposed to the noise of 10 M16 rifle shots. Immediately after the exposure, saline was then applied to one (control) ear and non-toxic concentrations of leupeptin determined in the first phase of the study were applied to the other ear, for four consecutive days. RESULTS Eight days after the exposure, the threshold shift (ABR) in the control ears was significantly greater (44 dB) than in the leupeptin ears (27 dB). CONCLUSION Leupeptin applied to the middle ear cavity can reduce the hearing loss resulting from exposure to impulse noise.
Calcium activated proteases, or calpains, play an important role in neurodegeneration. In some cases, neural degeneration can be significantly reduced by leupeptin, a potent calpain inhibitor. To determine if leupeptin could protect against noise-induced hearing loss and hair cell loss, we infused leupeptin into scala tympani of one cochlea before, during and after a 14-day exposure to a 100 dB...متن کامل
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Introduction: It has been shown that low levels of pigmentation increase susceptibility to noise-induced hearing loss in humans. For this reason, white populations develop more pronounced noise- induced hearing loss in comparison to black populations. Similarly, blue-eyed individuals exhibit greater temporary threshold shift than brown-eyed subjects; still, no strong correlation has been veri...متن کامل
Preconditioning by the inhalation of pure oxygen protects rat’s cochlear function against noise-induced hearing loss
Background: Occupational noise-induced hearing loss (ONIHL) is a hearing disorder that affects workers all over the world. Preconditioning with several mild or less potent stressors will effectively prevent the development of noise-induced hearing loss. This study investigated the possible preventive effects of normobaric hyperoxia preconditioning on preventing the noise-induced hearing impairm...متن کامل
Introduction: Nowadays, noise exposure is one of the most important industrial health problems. Noise exposure can cause hearing loss and many other health problems. So, paying attention to the noise exposure problem should be of main priority in industrial health programs. This study was conducted in an oil producing region, aimed to assess noise pollution and noise induced hearing loss. Met...متن کامل