Noise-induced alteration in expression patterns of cystathionine-γ-lyase in rat cochlea

Objective To reveal cystathionine-γ-lyase (CSE) expression pattern and localization in the adult rat cochlea and their changes following noise exposure. Methods An immunohistochemistry method was used to detect expression of CSE in the cochlea tissue in 32 adult Sprague Dawley (SD) rats without noise exposure and at.1 day, 1 week or 3 weeks after exposure to white noise at 110 dB SPL. Differences in CSE expressions with and without noise exposure were examined using RT-PCR. Results CSE was expressed in the stria vascularis, spiral ligaments, microvascular and vascular endothelium of the modiolar artery, but not in the organ of Corti and spiral ganglion cells. The expression level of CSE mRNA increased at 1 day and 1 week following noise exposure, but decreased at 3 weeks. Conclusion These findings suggest that CSE is expressed in the normal rat cochlea, and its reduced expression after noise exposure may be related to regulation of cochlear blood flow.