• 作者： 許權振; 林凱南
• 作者服務機構： 台大醫學院耳鼻喉科
• 中文摘要： 內淋巴水腫患者會有聽力障礙，但是其內耳的病理變化卻顯示耳蝸內聽覺毛細胞和血管紋的破壞或缺損並不明顯。內淋巴水腫之實驗動物模式也證實在耳蝸聽覺毛細胞和血管紋還沒有出現明顯的組織病理變化前，內耳的聽覺功能就開始減退。內耳正常聽覺功能的維持有賴於內淋巴液中之高鉀離子濃度和低鈉離子濃度。耳蝸內之碳酸脫水酵素一直被認為是調節內淋巴液及其所含離子濃度的重要酵素之一。本研究之目的乃在探討早期內淋巴水腫之內耳聽覺功能減退是否與耳蝸內碳酸脫水酵素活性的變化有關。天竺鼠內淋巴水腫耳蝸及正常耳蝸之60um厚切片，以組織化學法來染出耳蝸內之碳酸脫水酸素活性。結果雖然存活8週之第二組天竺鼠的聽性腦幹反應顯示其內耳聽覺功能有意義減退，但不論存活4週或8週之內淋巴水腫耳蝸之血管紋及聽覺毛細胞的碳酸脫水酵素活性並未減少。由本研究結果得知欲明暸碳酸脫水酵素在內淋巴水腫引起的聽覺功能減退所扮演的角色，則必須作進一步的研究。
• 英文摘要： Normal auditory function depends on maintenance of the unique ion composition in the endolymph.Carbonic anhydrase in the inner ear has been suggested to play an important role in maintaining the ionconcentration and regulating fluids of the inner ear. Cochlear dysfunction may indicate changes in thebiochemical components and osmotic pressure of the inner ear fluids as well as inadequate generation ofintracellular metabolic energy. Dysfunction of the inner ear was investigated in the early stages of endolym-phatic hydrops. Normal adult albino guinea pigs were operated on to obliterate the endolymphatic ductsand sacs of the right ears to induce endolymphatic hydrops. The auditory function of experimental guineapigs was assessed according to the difference between the preoperative and postoperative hearing thresholdsof the auditory brainstem response (ABR). Vibratome sections of the hydropic cochlea (right) and controlcochlea (left) were stained histochemically for the activities of carbonic anhydrase in this study. Decreasedactivity of this enzyme was not shown consistently in the stria vascularis and organ of Corti of the hydropiccochlea in the early stage of endolymphatic hydrops whereas auditory dysfunction in the hydropic ear wasnoted from the ABR threshold for the experimental animals with 2 months survival．The results of thepresent study suggest that further investigation concerning the role of carbonic anhydrase in the cochlearauditory function is necessary.
• 中文關鍵字： carbonic anhydrase; histochemistry; auditory brainstem response; endolymphatic hydrops.
• 英文關鍵字： --