噪声暴露对豚鼠血迷路屏障通透性的影响及其可能机制

The effect of noise exposure on the permeability of the blood labyrinth barrier of guinea pig and its possible mechanisms

为了探讨噪声暴露对豚鼠血迷路屏障通透性的影响及ERK1/2磷酸化在此过程中的作用,本文将豚鼠随机分为噪声暴露组和对照组;暴露组又分为两组,暴露时间分别为4 h和6 h。然后用Evans蓝染色和硝酸镧示踪法检测血迷路屏障的通透性,Western blot方法检验耳蜗组织中ERK1/2及其磷酸化蛋白的表达。结果显示:噪声暴露后4 h和6 h,耳蜗组织Evans蓝的染色强度均显著高于对照组(P<0.05);对照组镧颗粒仅滞留在血管纹毛细血管腔内,噪声暴露组镧颗粒分别见于毛细血管腔、血管内皮细胞和血管周围组织内;另外,噪声暴露组(4 h和6 h)耳蜗组织ERK1/2水平与对照组接近,但ERK1/2的磷酸化程度明显增加;两种噪声暴露处理对豚鼠血迷路屏障通透性及ERK1/2磷酸化水平的影响存在明显的剂量依赖效应;ERK1/2抑制剂PD98059可部分降低血迷路屏障的通透性。以上结果提示噪声暴露可增加血迷路屏障的通透性,其机制可能是通过诱导ERK1/2磷酸化来实现的。

In order to examine the effect of noise exposure on the permeability of blood labyrinth barrier （BLB） of guinea pig and the possible involvement of ERK1/2 phosphmylation, the guinea pigs were randomly divided into two groups, noise exposure group and the control group. The noise exposure groups were then divided into two subgroups according to the exposure times （4 or 6 h）, respectively. Evans blue dye and lanthanum nitrate were used to investigate the permeability of BLB after noise exposure. The expression of phospborylated ERK1/2 was detected with Western blot method. The results showed that the Evans blue staining intensity was significantly higher than the contral group in cochlea after noise exposure 4 or 6 h （P 〈0.05）. The lanthanum nitrate granules were kept in the capillary vessels in the stria vascularis of the control group. However, the lanthanum nitrate granules were observed in the capillary vessels, the vascular endothe- lial cells and the perivascular tissues, of the noise exposure group. The expression level of ERK1/2 in noise exposure group （ 4 or 6 h） was similar to that of control group, while noise exposure induced significantly increased phosphorylation of ERK1/2. There is a dose-dependent effect of exposure time on the permeability of BLB as well as the phosphorylation of ERK1/2. Furthermore, the treatment of ERK inhibitor PD98059 partly decreased the permeability of BLB. The present results suggest that the noise exposure results in the increase of BLB permeability and the induction of ERK1/2 phosphorylation may be involved in the process.