Article
Quantitative alterations of the estrogen-receptor β in the cochlea of the guinea pig after noise exposure
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Published: | August 10, 2015 |
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Introduction: Recently, the protective effect of the estrogen-receptor β (ERβ) was demonstrated after intensive noise exposure. The aim of the present study was to evaluate if even a moderate noise exposure was able to up-regulate ERβ-expression in the cochlea and to identify the affected regions.
Material and methods: Male guinea pigs (n=5) were exposed to 90 dB (SPL) for 1 h. Ears of un-exposed animals (n=5) were used as controls. The cochleae were removed, fixated and embedded in paraffin. The ERβ-expression was localized in six cochlear regions by immuno histochemistry. Staining intensities were quantified by computer.
Results: The basal ERβ-expression of unexposed ears revealed similar values for the stria vascularis, the organ of Corti, the interdental cells, and the nerve fibers. Smaller staining intensities were found in the fibrocytes of the Limbus and in the spiral ligament. The strongest ERβ-expression was identified for the third cochlear turn. Noise exposure for 1 h resulted in an increase in ERβ-expression in all cochlear regions. At the level of the individual ear, clear statistical associations were found comparing the stria vasculars and the spiral ligament or the interdental cells, or the fibrocytes of the Limbus.
Conclusion: Even a moderate noise exposure resulted in an increase in ERβ-expression in all cochlear regions. Current investigations are focused on its functional impact.