强化铁营养防治爆震性聋的初步研究

An experimental study of the effects of fortified iron nutrition on blast exposure hearing damage in Wistar rats

目的 探讨应用强化铁营养防治爆震性聋的可能性。方法 30只体重 2 0 0 g左右的健康Wistar大鼠被随机分为A、B两组 ,每组 15只 ,A组喂标准饲料 ,B组喂强化铁饲料。将A、B两组同时暴露于 172dBSPL强脉冲噪声下 ,共 30次 ,分别测定爆震前后大鼠的听性脑干反应 (ABR)阈值 ,扫描电镜观察耳蜗超微结构变化。结果 爆震后 3h、3d、11d和 2 1d ,B组大鼠ABR阈值显著小于A组。扫描电镜观察到爆震后 3h ,A组大鼠外毛细胞静纤毛排裂扭曲、倒伏、紊乱、融合及部分缺失 ,B组大鼠外毛细胞静纤毛有轻度紊乱及松散 ;3d后A组大鼠外毛细胞静纤毛病变无明显恢复 ,B组大鼠外毛细胞静纤毛病变已不明显 ;11d后A组病变减轻 ,B组病变基本恢复 ;2 1d后A组病变明显减轻 ,但有部分病变未完全恢复 ,B组病变均完全恢复。

Objective To study the effects of fortified iron nutrition on blast exposure hearing damage in Wistar rats. Methods 30 Wistar rats were randomized into two groups (A and B, each of 15 animals ). The group A rats were fed with normal dietary iron and group B rats with fortified iron nutritional diet. They were simultaneously exposed to blast at 172 dB SPL. ABR thresold shifts were carried out in the same animals before and after blast exposure. The morphologic cochlear changes were examined by scanning electronmicroscopy. Results The ABR threshold shifts at 3 h,3 d,11 d,and 21 d after blast exposure in group B rats were significantly less than those in group A ones. No permanent threshold shifts was seen in any of the group B rats. Scanning electron microscopy indicated: the pathologic changes of the outer hair cells stereocilia at 3 h after blast exposure were much less severe in group B than those in group A, and 21 d afterwards,the stereocilia appeared perfectly normal and well defined in group B, whereas in group A there were still some abnormalities of stereocilia remained.Conclusion Adequate and well designed fortified iron nutritional diet can protect cochlear hair cells against blast exposure.