Pender Daniel J
Department of Otolaryngology, Columbia Presbyterian Medical Center, New York, NY, USA.
Laryngoscope. 2003 Feb;113(2):343-8. doi: 10.1097/00005537-200302000-00026.
The objective of the study was to determine whether a selective vestibular hair cell toxicity with sparing of the cochlear hair cells could be achieved by infusing different concentrations of gentamicin into the middle ears of adult cats.
Prospective experimental animal study treating only the left ear of each cat, the right ear serving as individual control.
Gentamicin solution at concentrations of either 30 or 3 mg/mL was infused daily into the left middle ear of adult cats until overt ataxia occurred. After 1 month or 6 months, each cat was killed and its temporal bones prepared for optical microscopy.
Animals treated with 30 mg/mL gentamicin until ataxic required a median of five daily doses. These animals had clear-cut cochlear basal turn hair cell losses accompanying toxic lesions in the utricle and cristae. In contrast, animals treated with 3 mg/mL gentamicin until ataxic required an average of 19 daily doses. These animals had lesions restricted to the utricle and cristae with sparing of the cochlea hair cells. Animals that failed to develop ataxia manifested neither lesions of the cochlear nor vestibular hair cells.
Gentamicin tympanoclysis in the cat animal model, using a dilute solution and continued once daily until clinical ataxia occurs, is capable of producing selective vestibular hair cell toxicity while sparing cochlea hair cells.
本研究的目的是确定通过向成年猫中耳注入不同浓度的庆大霉素，是否能够实现选择性的前庭毛细胞毒性而不累及耳蜗毛细胞。
前瞻性实验动物研究，仅治疗每只猫的左耳，右耳作为个体对照。
将浓度为30或3mg/mL的庆大霉素溶液每日注入成年猫的左中耳，直至出现明显共济失调。1个月或6个月后，处死每只猫，并将其颞骨制备用于光学显微镜检查。
用30mg/mL庆大霉素治疗至共济失调的动物，中位需要5次每日剂量。这些动物在椭圆囊和嵴顶出现毒性病变的同时，耳蜗基底转毛细胞明显丢失。相比之下，用3mg/mL庆大霉素治疗至共济失调的动物平均需要19次每日剂量。这些动物的病变局限于椭圆囊和嵴顶，耳蜗毛细胞未受影响。未出现共济失调的动物，耳蜗和前庭毛细胞均未出现病变。
在猫动物模型中，使用稀释溶液并每日持续一次直至出现临床共济失调的庆大霉素鼓室注射法，能够产生选择性前庭毛细胞毒性，同时不累及耳蜗毛细胞。
