A study of the possible role of vasopressin in the formation of the endolymphatic hydrops

1)研制了一种测量豚鼠前庭-眼反射(VOR)的新装置。该系统由红外线摄像机、小型速度传感器、频率调制器和带有小动物头架的计算机控制转台组成。眼球运动对抗正弦旋转是由个人计算机完成的。2)从形态学和分子生物学的角度研究了加压素对大鼠内耳的影响。血管加压素用渗透压微泵皮下注射。慢性应用加压素可引起大鼠内淋巴积水，水通道蛋白-2在耳蜗囊和内淋巴囊中的表达均显著增加(p&lt；0.01)。3)观察V2拮抗剂(OPC-31260)对实验性大鼠内淋巴积水的影响及对AQP2mRNA表达的调节。鼓阶内注入3%OPV-31260可减少实验性豚鼠内淋巴积液。在聚合酶链式反应研究中，用LightCycler分析软件(版本3.3，罗氏诊断)对AQP2mRNA的表达进行了定量分析。静脉注射OPC-31260后，耳蜗区和内淋巴囊中AQP2和β-肌动蛋白mRNA的比值均显著降低(t检验)。这些结果表明，内耳的水平衡是通过血管加压素-水通道蛋白2(VP-AQP2)系统来调节的，V_2拮抗剂(OPC-31260)是治疗梅尼埃病的有前途的药物。

1) New device to measure vestibular-ocular reflex (VOR) of guinea pigs was developed. This system consists of an infra-red eye camera, a small velocity sensor, a frequency modulator and a computer-controlled turn-table wit a head holder for small animals. Eye movement against sinusoidal rotation was carried out by a personal computer. VOR analysis was possible if pigment guinea pigs are used as experimental animals.2) The influence of vasopressin on the rat inner ear was investigated morphologically and molecular-biologically. Vasopressin was subcutaneously applied with an osmotic mini-pump. Chronic application of vasopressin produced endolymphatic hydrops and a significant increase in aquaporin-2 mRNA expression both in the cochlea and in the endolymphatic sac (p<0.01).3) The influence of V2-antagonist (OPC-31260) on experimentally-induced endolymphatic hydrops and on a regulation of AQP2 mRNA expression in the rat inner ear was investigated. The infusion of 3% OPV-31260 into the scala tympani decreased experimentally-induced endolymphatic hydrops in guinea pigs. In the PCR study, quantitative analyses of AQP2 mRNA expression were performed with the LightCycler analysis software (version 3.3, Roche Diagnostics). An intrvenous injection of OPC-31260 resulted a significant decrease in the ratio of AQP2 and β-actin mRNA both in the cochlea and in the endolymphatic sac (t-test). These results indicated that water homeostasis in the inner ear is regulated via vasopressin-aquaporin2 (VP-AQP2) system, and that V_2-antagonist (OPC-31260) is the promising drug for the therapy of Meniere's disease.