老龄豚鼠耳蜗血管纹NOS活性与电生理关系研究

Study on Relationship between NOS Activity at Stria Vascularis and Electrophysiology of Cochlea in Aging Guinea Pigs

本文采用ＮＡＤＰＨｄ组织化学、图象分析及听觉电生理技术，研究豚鼠衰老过程中血管纹一氧化氮合酶（ＮＯＳ）活性的变化与蜗内电位（ＥＰ）及复合动作电位（ＣＡＰ）的关系，探讨ＮＯＳ在老年性聋发病过程中的可能作用。结果发现，３月龄豚鼠ＥＰ值最大，为８６３２±３２４ｍＶ，随着豚鼠的衰老ＥＰ值逐渐下降，ＣＡＰＮ１波振幅的变化规律与ＥＰ的变化规律一致。ＣＡＰＮ１波潜伏期有逐渐延长的趋势。组织化学染色表明，ＮＯＳ阳性反应主要位于血管纹边缘细胞的胞浆内，随着豚鼠的衰老，血管纹ＮＯＳ阳性反应逐渐减弱，除２周龄组外，ＮＯＳ活性与ＥＰ及ＣＡＰＮ１波振幅有正相关趋势。结果提示，耳蜗血管纹ＮＯＳ可能参与内耳微循环及微环境稳定的调节。

This experiment adopted NADPH diaphorase histochemistry method,image pattern analysis and auditory electrophysiological technique to study the relationship between nitric oxide synthase (NOS) activity and electric potential (EP) and compound action potential (CAP) at cochlea and to explore the possible role of NOS in pathogenic process of senile deafness.The results showed: EP value reached the highest,86 36±3 24mV,in 3 month old guinea pigs and reduced with the senility of guinea pigs.Amplitude of CAP N1 change was consistent with that of EP,latent period of CAP N1 tended to increase.NADPH diaphorase histochemistry staining indicated that NOS positive respose were mainly located in cytoplasm of margin cells in stria vascularis; and NOS positive reaction decreased with senility of guinea pigs.NOS activity in tria vascularis had positive correlation with EP and CAP except for 2 week old group.It is suggested that NOS in stria vascularis might be involved in controling and stabilizing microcirculation of inner ears and might accelarate evolvement of stria vascularis of young guinea pigs.Reduction of NOS content and activity might be main factor leading to senile deafness.