内耳色素与爆震性听损伤

目的 探讨内耳色素与爆震性听损伤的关系。方法 选用豚鼠４８只,分为：白化豚鼠爆震组,杂色豚鼠爆震组,正常对照组。爆震前及爆震后６小时、１、２、７、１４、２１天测定Ａ、Ｂ组豚鼠ＡＢＲ阈值。处死豚鼠做耳蜗铺片、耳蜗树脂包埋半薄切片、耳蜗扫描电镜制样,观察耳蜗内色素及耳蜗损伤情况。结果 光镜下杂色豚鼠可见耳蜗内色素颗粒,而白化豚鼠未见。爆震后白化豚鼠听力损伤比杂色豚鼠严重,其听力恢复亦较杂色豚鼠慢。爆震

Relationship Between Melanin in Inner Ear and Blast-induced Hearing Loss

Objective to elucidate the relationship between blast-induced hearing loss and pigmentation.Methods twenty-four albino guinea pigs and twenty-four pigment guinea pigs were divided into four groups:the blast-exposed albino guinea pig group(18)and control albino guinea pig group(6),the blast-exposed pigment guinea pig group(18) and control pigment guinea pig group(6).Using ABR to measure the threshold before exposure (173.0 dB SPL 5 rounds)and at the six different time points,which were 6 hours,1 day,2 days,7 days,14 days and 21 days after exposure.Changes in the hair cell and stria vascularies were studied using cochlear pave sections,cochlear semi-thickness microtome sections and scanning electron microscopy .Results The threshold shifted after exposure.The hearing functional changes in the cochlear were more severe in the albino animals as well as the pathological changes.Conclusion the pathophysiology of blast-induced hearing loss involves cochlear mechanisms related to radical oxygen species(ROS)as melanin both generates and neutralizes ROS.On the other hand,melanin participates in maintaining the balance of endolymphatic calcium.