豚鼠耳蜗顶部区域微循环障碍的实验研究

Characteristics of Hearing Loss Caused by Local Microcirculatory Disorders in the Cochlea Apical Part of Guinea Pigs

目的 研究豚鼠耳蜗顶部区域微循环障碍的听力损伤特点，建立以低频损伤为主的听力损伤模型。方法 光化学法诱导豚鼠耳蜗顶部区域微循环障碍，常规火棉胶切片观察耳蜗形态学变化，再用Ｍａｄｓｅｎ２２５０诱发电位系统记录各频率声刺激诱发的ＣＡＰ和ＣＭ。结果 各频率ＣＡＰ－Ｎｌ潜伏期延长值、ＣＡＰ阈移、ＣＡＰ－Ｎ１和ＣＭ振幅下降示其听力损伤以低频较重，其血栓形成的范围以耳蜗顶回及第三回血管纹和螺旋韧带为主。结论 耳蜗顶部区域的局部微循环障碍可以导致低频范围为主的听力损伤。

Objective To study the characteristics of hearing loss caused by local microcirculatory disorders in the cochlea apical part of guinea pigs. Methods The local microcirculatory disorders in the cochlea apical part of guinea pigs were caused by photochemical reaction. Morphological changes were observed by light microscope. The CAP - N1 amplitude, CAP - N1 latency, CAP - N1 threshold shift and CM amplitude which were evoked by short tone burst were recorded by Madsen 2250. Re- sults Histopathological changes showed that microthrombosis in the capillaries of stria vascularies and spiral ligment were located in the apical and third turn of cochlea. The CAP - N1 amplitude, CAP - N1 latency, CAP-N1 threshold shift and CM amplitude showed that the hearing loss was remarkable in the low - range frequencies. Conclusion When the local microcirculatory disor- ders in the cochlear apical part took place, the hearing loss was more marked in the low - range frequencies.