脑缺血再灌注对大鼠耳蜗形态学及听觉的影响

目的：为探讨脑缺血再灌注对大鼠耳蜗形态学及听觉的影响。方法：采用闭塞大鼠肮脏了缺血模型，观察了脑缺血３０分钟及再灌注不同时间大鼠耳蜗结构和听阈的动态变化，形态学观察应用光镜、扫描电镜与透射电镜，听力测定采用４０ＨＺ听上关电位（４０ＨＺＡＥＲＰ）技术。结果：缺血３０分钟和再灌注２小时、２４小时、７２小时４０ＨＺＡＥＲＰ反应阈与缺血前比较显著提高（Ｐ〈０．０１），随或注延长听阈逐渐降低。病理变化特点是

EFFECT OF BRAIN ISCHEMIA AND REPERFUSION ON MORPHOLOGY AND HEARING OF COCHLEAS IN RAT

To investigate the effect of brain ishchemia and reperfusion on morphology and hearing of cochlea, a four--vessel occlusion rat model was used, and the changes of the hearing thresholds and structure of the cochlea were observed at 30 min after brain ishcemia and at different reperfusion time. Morphological observation was made by light scanning and transmission electron microscopy, while the hearing thresholds were recorded with 40Hz auditory event related potential (40Hz AERP). The results showed that after 30 min ischemia and reperfusion for 2 h, 24 h and 72 h, the 40Hz AERP response threshold was significantly higher than before the ischemia(P< 0.01). Hearing thresholds decreased progressively with the prolongation of the reperfusion time. The pathological examination showed shortening or swelling and necrosis of some outer hair cells of Corti's organ, derangement or shedding of the sensory cilias, the reduced number of spiral ganglion cell, hydropic degeneration of the mitochondria, dilatation of the endoplasmic reticulum. These results suggested that sudden hearing loss and cochlea cell damage could be induced by brain ischemia and reperfusion. The study provides the experimental evidence for the prevention and therapy of ischemic damage of inner ear.