Hashimoto Yasuyuki, Iwasaki Satoshi, Mizuta Kunihiro, Arai Maki, Mineta Hiroyuki
Department of Otolaryngology, Hamamatsu University School of Medicine, Hamamatsu city, Japan.
Acta Otolaryngol. 2007 Feb;127(2):116-21. doi: 10.1080/00016480600794438.
Short-term local application of kanamycin by the microcatheter method can control the region and severity of drug effect on the cochlea by changing the concentration and administration time.
To investigate the effect of short-term round window administration of kanamycin by the microcatheter method on cochlear stereociliary bundle loss in a guinea pig model.
Two concentrations and two time periods were used for drug administration to the inner ear. In groups of six animals, a total dose of 172.5 mg/ml or 345 mg/ml of kanamycin was instilled at the rate of 0.1 ml/h into the round window niche over either a 1 h or 2 h period by the microcatheter method. One group of six animals received a saline infusion as a control. The animals were sacrificed after 4 days and stereociliary bundle loss was observed by SEM. Functional changes were evaluated by auditory brainstem response.
With regard to the severity of the damage, higher drug concentrations were associated with more severe effects. The severity of damage was the same when the same total dose was used; however, it was found that when the dose was administered over a longer period, the damage region was wider. The functional changes also corresponded with the morphological changes.
通过微导管法短期局部应用卡那霉素，可通过改变浓度和给药时间来控制药物对耳蜗作用的区域和严重程度。
在豚鼠模型中，研究通过微导管法经圆窗短期给予卡那霉素对耳蜗静纤毛束损失的影响。
采用两种浓度和两个时间段向内耳给药。将六只动物分为一组，通过微导管法以0.1 ml/h的速率在1小时或2小时内将172.5 mg/ml或345 mg/ml的卡那霉素总剂量滴入圆窗龛。一组六只动物接受生理盐水输注作为对照。4天后处死动物，通过扫描电子显微镜观察静纤毛束损失情况。通过听性脑干反应评估功能变化。
就损伤的严重程度而言，较高的药物浓度会产生更严重的影响。使用相同总剂量时，损伤的严重程度相同；然而，发现当在更长的时间段内给药时，损伤区域更宽。功能变化也与形态学变化相对应。
