糖皮质激素受体在豚鼠耳蜗的分布及声损伤对其表达的影响

Distribution of glucocorticoid receptor in cochlea of guinea pigs and the effects of acoustic trauma on its expression

目的研究糖皮质激素受体(GR)在豚鼠耳蜗的分布及声损伤对豚鼠耳蜗GR表达的影响。方法将豚鼠随机分为2组:实验组豚鼠在强度115dBSPL的白噪声中暴露3h。暴露结束后2h,断头取耳蜗。对照组豚鼠不做处理,取耳蜗。制备耳蜗冷冻切片,采用免疫荧光技术观察豚鼠耳蜗的GR表达情况,并进行荧光强度半定量分析。结果①豚鼠耳蜗GR主要的阳性部位:螺旋韧带、血管纹、骨螺旋缘、Corti器及螺旋神经节。螺旋韧带、血管纹、骨螺旋缘及螺旋神经节等区域的GR荧光强度差异无统计学意义(P>0.05),上述各区域的GR荧光强度与Corti器的GR荧光强度差异有统计学意义(P<0.05)。②声损伤后,豚鼠耳蜗的GR荧光强度在骨螺旋缘、Corti器及螺旋神经节较对照组差异无统计学意义(P>0.05);螺旋韧带、血管纹区域荧光强度较对照组明显减低,差异有统计学意义(P<0.01)。结论 GR分布于豚鼠耳蜗的螺旋韧带、血管纹、Corti器和螺旋神经节,其中螺旋韧带、血管纹表达最强,Corti器表达最弱;声损伤降低耳蜗各区域GR的表达,以血管纹、螺旋韧带最明显。

Objective To explore the distribution of glucocorticoid receptor（GR） in cochlea of guinea pigs and the effects of acoustic trauma On its expression. Methods Albino guinea pigs were randomly divided into 2 groups ： experimental group and control group. Noise exposure （white noise, 115 dB SPL,3 h） was exerted in experimental group. Decapitation and cochlear separation was done 2 hours after noise exposure. Empty treatments were done in the control group. Frozen sections were prepared. Immunofluorescent technique fixing and fluorescence intensity semiquantitative analysis were detected for studying the distribution of GR in cochlea of guinea pigs and the effects due to the acoustic trauma. Results ①The fundamental positive positions of GR were located in spiral ligament, stria vascularis, spiral lira- bus, organ of Corti and spiral ganglions. For fluorescence intensity of GR, there was no significant difference in spiral lig- ament, stria vascularis, spiral limbus and spiral ganglions （P 〉 0. 05 ）. However, there was significant difference between these positions and organ of Corti （ P 〈 0.05 ）. ② The fluorescence intensities of GR located in spiral limbus, organ of Corti and spiral ganglions were similar in noise exposure group and control group （P 〉 0.05）. The fluorescence intensities of GR in spiral ligament, stria vascularis were much lower in noise exposure group （P 〈 0. 01 ）. Conclusions The distribution of GR in cochlea of guinea pigs were located in spiral ligament, stria vascularis, spiral limbus, organ of Corti and spiral ganglions. The highest and least position were lateral wall and organ of Corti respectively. Acoustic trauma could decrease GR expression in all positions of cochlea, particularly in spiral ligament and stria vascularis.