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目的探讨应用强化铁营养对抗稳态噪声致聋作用的可能性。方法４０只健康幼龄Ｗｉｓ－ｔａｒ大鼠按随机化原则分为两组，每组２０只：Ａ组饲标准饲料；Ｂ组饲强铁化饲料。将Ａ、Ｂ两组大鼠同时暴露于１１０ｄＢＳＰＬ２０～１００００Ｈｚ稳态白噪声，持续４０分钟。根据暴露前后听性脑干反应（ＡＢＲ）阈差值判定听力阈移，扫描电镜及光镜下观察耳蜗显微结构和听毛细胞表面超微结构变化。结果暴露后２小时、３天和１１天的Ｂ组听力阈移值显著小于Ａ组；暴露后２１天，虽然两组听力阈移均数值的差异无显著意义，但Ａ组ＡＢＲ阈值均数仍显著大于该组大鼠噪声暴露前平均听阈。扫描电镜下观察，暴露后２小时的Ａ组大鼠外毛细胞静纤毛出现严重扭曲、倒伏、排列紊乱等病理变化；３天后，上述病变明显减轻；２１天后，部分听毛细胞静纤毛排列紊乱仍未能完全恢复。在Ｂ组大鼠，外毛细胞静纤毛暴露２小时后有轻度扭曲及排列紊乱，３天后这些病变基本恢复，２１天后外毛细胞静纤毛形态完全恢复正常。结论强化铁营养具有对抗稳态噪声听损伤作用，其机理可能与其对含铁酶类活性的增强作用有关
Objective To explore the possibility of applying iron fortification to deafness caused by steady-state noise. Methods Forty healthy Wis-tar rats were randomly divided into two groups according to the principle of randomization: group A received standard feed; group B fed iron-enriched feed. The A and B groups of rats were simultaneously exposed to steady-state white noise of 110 dBSPL at 20 ~ 10000 Hz for 40 minutes. The hearing thresholds were determined according to the difference of threshold of auditory brainstem response (ABR) before and after exposure. The ultrastructure of cochlear ultrastructure was observed under scanning electron microscope and light microscope. Results After 2 hours, 3 days and 11 days of exposure, the hearing threshold of group B was significantly lower than that of group A. After 21 days of exposure, although there was no significant difference in hearing threshold between the two groups, the average ABR threshold in group A Significantly higher than the average noise threshold before the rats in this group were exposed. Scanning electron microscopy showed that after 2 hours of exposure, the outer cilia of the outer hair cells in group A appeared serious distortion, lodging and disordered pathological changes. After 3 days, the above lesions were significantly reduced; Still not fully recovered. In group B, the outer hair cells were mildly twisted and disordered after 2 hours of exposure to static cilia. After 3 days, these lesions recovered, and the shape of the outer hair cells completely recovered to normal after 21 days. CONCLUSIONS: Iron fortification has a protective effect against steady-state noise and its mechanism may be related to the enhancement of iron-containing enzyme activity