Kitahara Tadashi, Maekawa Chie, Kizawa Kaoru, Horii Arata, Doi Katsumi
Department of Otolaryngology, Osaka University, School of Medicine, Suita-city, Osaka, Japan.
Otol Neurotol. 2009 Sep;30(6):812-9. doi: 10.1097/MAO.0b013e3181b11db5.
There are some kinds of sicknesses provoked by inadequate adaptation to physical and/or psychogenic stress in daily life. Delayed endolymphatic hydrops (DEH) is an inner ear disease like Ménière's disease (MD) characterized by episodic vertigo in the setting of preexisting unilateral deafness that especially occurs in civilized people with a stressful lifestyle. Its otopathologic finding was demonstrated to be inner ear endolymphatic hydrops through a temporal bone study in 1976, as in the case with MD in 1938. To elucidate the relationship between stress and the inner ear, we examined the plasma antidiuretic stress hormone vasopressin (pAVP) and its type 2 receptor (V2R) expression in the endolymphatic sac in patients with DEH.
A prospective molecular biological study.
Between 1998 and 2007, we enrolled 20 patients with ipsilateral DEH to examine their pAVP during remission from vertigo attacks. Plasma vasopressin was also examined in 87 patients with unilateral MD and 30 control patients with chronic otitis media. Using the real-time polymerase chain reaction method with tissue samples obtained during surgery, we examined V2R mRNA expression in the endolymphatic sac in 6 patients with ipsilateral DEH, 9 patients with unilateral MD, and 6 control patients with acoustic neuroma.
Plasma vasopressin (1.5 times versus controls; unpaired t test, p = 0.140) and V2R mRNA expression in the endolymphatic sac (35.8 times versus controls; unpaired t test, p = 0.002) were higher in patients with DEH compared with those with acoustic neuroma. There were no significant differences in pAVP or V2R expression in the endolymphatic sac between DEH and MD. Patients with DEH showed a significantly negative correlation between pAVP and V2R (Pearson test, r = -0.92, p = 0.009) as in those with MD (Pearson test, r = -0.68, p = 0.043).
Civilized people are frequently exposed to stress in their daily life, and pAVP can easily become elevated at any time. Therefore, a negative feedback system between pAVP and V2R in the endolymphatic sac may function for inner ear fluid homeostasis against stress-induced increases in pAVP. For the pathogenesis of endolymphatic hydrops resulting in vertigo attacks in patients with DEH as well as MD, pAVP may represent a matter of consequence, but V2R overexpression in the endolymphatic sac could be much more essential as a basis for these diseases.
日常生活中，有一些疾病是由对身体和/或心理压力适应不足引发的。迟发性内淋巴积水（DEH）是一种类似于梅尼埃病（MD）的内耳疾病，其特征是在已有单侧耳聋的情况下出现发作性眩晕，尤其多见于生活压力大的文明人群。1976年通过颞骨研究证实其耳病理学表现为内耳内淋巴积水，就如同1938年对MD的研究结果一样。为阐明压力与内耳之间的关系，我们检测了DEH患者血浆抗利尿应激激素血管加压素（pAVP）及其在内淋巴囊中的2型受体（V2R）表达。
一项前瞻性分子生物学研究。
在1998年至2007年期间，我们纳入了20例同侧DEH患者，在眩晕发作缓解期检测他们的pAVP。还检测了87例单侧MD患者和30例慢性中耳炎对照患者的血浆血管加压素。使用实时聚合酶链反应方法，对6例同侧DEH患者、9例单侧MD患者和6例听神经瘤对照患者手术中获取的组织样本进行检测，以研究内淋巴囊中V2R mRNA的表达。
与听神经瘤患者相比，DEH患者血浆血管加压素水平（是对照组的1.5倍；非配对t检验，p = 0.140）以及内淋巴囊中V2R mRNA表达水平（是对照组的35.8倍；非配对t检验，p = 0.002）更高。DEH与MD患者在内淋巴囊中pAVP或V2R表达上无显著差异。与MD患者一样（Pearson检验，r = -0.68，p = 0.043），DEH患者pAVP与V2R之间呈显著负相关（Pearson检验，r = -0.92，p = 0.009）。
文明人群在日常生活中经常面临压力，pAVP随时可能轻易升高。因此，内淋巴囊中pAVP与V2R之间的负反馈系统可能针对压力诱导的pAVP升高，对内耳液体稳态发挥作用。对于导致DEH以及MD患者眩晕发作的内淋巴积水的发病机制而言，pAVP可能是一个重要因素，但内淋巴囊中V2R的过度表达作为这些疾病的基础可能更为关键。
