应用微型渗透压泵进行耳蜗慢性灌流的方法

The technique of chronic infusion of drugs into the cochlea by an osmotic pump

目的介绍微型渗透压泵进行耳蜗灌注的方法，达到耳蜗慢性给药。方法将耳蜗埋置管置于５只灰鼠耳蜗底回鼓阶中，再将渗透压泵埋置于动物背部，利用泵内、外渗透压之差将泵内液体缓慢挤压释放。观察耳蜗灌流Ｈａｎｋ液（３耳）和Ｌｂｕｔｈｉｏｎｉｎｅ［Ｓ，Ｒ］ｓｕｌｆｏｘｉｍｉｎｅ（ＢＳＯ）液（２耳）对下丘电位和耳蜗毛细胞的影响。结果应用渗透压泵耳蜗灌流Ｈａｎｋ液后，下丘电位阈值维持正常，耳蜗毛细胞无损伤；灌流ＢＳＯ液１４天后，所测频率（１、２、４和８ｋＨｚ）的下丘电位阈值平均升高２８ｄＢ，内耳毛细胞平均缺失３９．３％，缺失分布于耳蜗各回，表明渗透压泵工作良好。结论应用渗透压泵进行耳蜗灌流是一种慢性耳蜗给药的有效方法，灌流Ｈａｎｋ液不会对耳蜗产生明显影响。

Objective To introduce a method of chronic infusion of drugs into the cochlea using a osmotic pump. Methods A stainless steel tube was surgically implanted into the basal turn of the chinchilla cochlea and connected to the pump. To assess the reliability of the procedure, and the pump, Hank's solution or L buthionine sulfoximine (BSO) was infused into the cochlea by this pump and inferior colliculus (IC) potential and hair cell morphology were examined. Results In three Hank's solution infused cochleas, the thresholds of IC potential were kept in the normal level and no hair cell loss was found 14 days after the beginning of the infusion, suggested that the pump implantation and Hank's solution infusion had no significant effects on the cochlear functions. In contrast, threshold shifts of IC potentials and hair cell loss were found in two BSO infused animals, suggested that the infused solution had distributed into the whole cochlea. Conclusion This study indicates that the osmotic pump can be used in chronic delivery of experimental drugs into the cochlea.