豚鼠耳蜗螺旋动脉结构和功能异常与代谢性老年性耳聋的相关性研究

代谢性老年性耳聋发病的关键因素是血管纹毛细血管的异常而导致供血不足，进而导致血管纹的功能降低。 血管纹毛细血管网的上游血管是耳蜗螺旋动脉，也是供应耳蜗血液的唯一动脉。 前期研究曾阐明耳蜗螺旋动脉的功能失常与突发性耳聋和美尼尔综合症有密切关联。 基于此发现，我们假设在老年性耳聋模型动物中耳蜗螺旋动脉结构和/或功能改变，会导致耳蜗的供血不足，而出现眩晕、耳鸣、甚至听力丧失。 本研究主要通过检测老年组与对照组豚鼠间的ABR听阈、耳蜗螺旋动脉的形态改变 (如动脉壁增厚、官腔狭窄等), 以及影响血管舒缩运动的因素 (如血管活性物质对血管直径的影响、血管细胞间缝隙连接通讯的变化, 以及平滑肌细胞增殖等），以阐明代谢性老年性耳聋的发病机制。

The key factor of pathogenesis of metabolic presbycusis is insufficient blood supply to cochlea induced by abnormity of capillaries of stria vascularisa resulting in dysfunction of stria vascularis. The upstream blood vessel of stria vascularis is spiral modiolar artery (SMA) that is the only artery providing blood swupply to cochlea. Previous studies have demonstrated that the dysfunction of cochlea spiral artery is closely related to sudden deafness and Meniere syndrome. Based on these findings, we hypothesize that the altered structure and/or function of SMA will cause insufficient blood supply to cochlear, which will induce vertigo, tinnitus, and hearing loss. In this study, we compared the differences between elderly and control groups of guinea pigs: the ABR threshold, the structure changes in SMA (e.g. arterial wall thickening and bureaucratic narrow), the response to vasoactive substances (e.g. the changes in vascular diameter, intercellular gap junction communication, and smooth muscle cell proliferation). The results from this study will provide better understanding of the pathogenesis of metabolic presbycusis.