Laurent C, Hellström S, Anniko M
Department of Oto-Rhino-Laryngology, Umeå University Hospital, Sweden.
Acta Otolaryngol. 1988 Mar-Apr;105(3-4):273-80. doi: 10.3109/00016488809097008.
1.9% hyaluronan (HA) (mol. wt. 3 x 10(6] was applied repeatedly into the middle ear of rats through a myringotomy. The function and structure of the cochlea was analysed by auditory brainstem recordings (ABR) at 2-31.5 kHz and by light microscopy. The myringotomy significantly impaired the ABR thresholds at frequencies below 8 kHz. Five days after the last application of HA, the ABR thresholds showed minor improvements at 6-8 kHz but were impaired at 12 and 20 kHz, as compared with control levels. One month after the last administration of HA, ABR thresholds were significantly improved as compared with the initial level at 2-6 kHz but normal at all other frequencies. After 3 months, all ABR thresholds had returned to the pre-treatment (normal) level. Five days after the last application of HA, the latencies for almost all frequencies were significantly prolonged for waves II and IV at the ABR threshold. After 3 months all latencies had returned to their pre-treatment (normal) values. Highly concentrated hyaluronan (1.9%) is free from ototoxicity but does have transient functional effects on the inner ear.
通过鼓膜切开术将1.9%的透明质酸（HA）（分子量3×10⁶）反复注入大鼠中耳。通过2 - 31.5千赫兹的听性脑干反应（ABR）和光学显微镜分析耳蜗的功能和结构。鼓膜切开术显著损害了8千赫兹以下频率的ABR阈值。在最后一次应用HA五天后，与对照水平相比，ABR阈值在6 - 8千赫兹处有轻微改善，但在12和20千赫兹处受损。在最后一次给予HA一个月后，与初始水平相比，2 - 6千赫兹处的ABR阈值显著改善，但在所有其他频率处均正常。三个月后，所有ABR阈值均恢复到治疗前（正常）水平。在最后一次应用HA五天后，在ABR阈值下，几乎所有频率的波II和波IV的潜伏期均显著延长。三个月后，所有潜伏期均恢复到治疗前（正常）值。高浓度透明质酸（1.9%）无耳毒性，但确实会对内耳产生短暂的功能影响。
