一氧化氮在豚鼠耳蜗作用的实验研究

为探讨ＮＯ在内耳的作用，采用外淋巴给药途径，观察一氧化氮气体（ＮＯ）、Ｌ－精氨酸、硝普钠及一氧化氮合酶（ＮＯＳ）拮抗剂Ｎ－甲基－Ｌ－精氨酸对耳蜗蜗内电位（ＥＰ）、复合动作电位（ＣＡＰ）及耳蜗微音器电位（ＣＭ）的影响。结果表明，Ｎ－甲基－Ｌ－精氨酸可以使ＥＰ减小５０％，ＣＡＰ振幅降低３３％及ＣＭ振幅略有降低，在此基础上，用Ｌ－精氨酸外淋巴灌流可以逆转Ｎ－甲基－Ｌ－精氨酸所致的改变。ＮＯ持外淋巴缓释能

Experimental study on the effect of nitric oxide on cochleas of guinea pigs]

The effects of nitric oxide (NO), 1-monoarginine (L-Arg), sodium nitroprusside (SNP) and N-methyl-1-monoarginine (NMLA) (which is an antagonist of nitric oxide synthase) on endocochlear potential, compound action potential(CAP) and cochlear microphonic(CM) of cochleas were studied by means of perilymphatic perfusion of the agents. The results showed that NMLA reduced EP, CAP and CM, L-Arg perilymphatic perfusion could reverse the change caused by NMLA. Continuous NO perilymphatic release restored the changes of EP, CAP and CM back to normal, sometimes above normal, followed by rapid reduction. After SNP perilymphatic perfusion, EP, CAP and CM went up transiently and then declined gradually and remained at a lower level. Addition of NMLA did not reverse the changes. The change of the latent period of CAP N1 and drift of CM was consistent with their amplitude changes. It was suggested that NO might help maintaining inner ear function under physiological condition and participate in controlling the micromechanical character and sensitivity of cochlear hair cells, undue expression of NO may cause toxicity to cochleas.