胱硫醚-γ-裂解酶在大鼠耳蜗的分布及其在噪声刺激后的表达变化

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

目的探讨大鼠耳蜗胱硫醚-γ-裂解酶(cystathionine-γ-lyase,CSE)的分布情况及在噪声刺激后的表达变化。方法通过免疫组织化学及免疫荧光染色技术,观察CSE在正常成年SD大鼠耳蜗内的分布及定位。32只SD大鼠被分成4组:正常对照组、1天组、1周组、3周组,后3组分别暴露于110dBSPL宽带白噪声中。采用逆转录-聚合酶链反应(RT-PCR)方法检测大鼠接受强噪声刺激前后CSE在耳蜗内的表达变化。结果CSE主要表达在大鼠耳蜗的血管纹,螺旋突,以及耳蜗微小血管处;在耳蜗内外毛细胞、各类支持细胞、盖膜及蜗神经节处未见明显表达。随着噪声刺激时间的延长,CSE在mRNA水平的表达呈先增长后下降的趋势。结论CSE在耳蜗内的分布及其在噪声刺激后的表达变化,提示其在改善耳蜗血循环方面可能发挥重要作用。

Objective To reveal cystathionine-γ-1yase （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.