豚鼠耳蜗毛细胞暴露非聚焦超声后的酶组织化学观察

Enzyme histochemistry study of non-focused ultrasound irradiating the cochlea in guinea pigs

目的 探讨非聚焦超声 (non focusedultrasound ,NFU)对耳蜗毛细胞的影响。方法 以A型超声波诊断仪为超声发射器 ,分别以 2 5MHz、8MHz照射各 15耳豚鼠耳蜗 6h后 30min和 8h行耳蜗基底膜毛细胞铺片及冰冻切片观察琥珀酸脱氢酶 (succinatedehydrogenase ,SDH)组织化学变化。结果 2 5MHz、8MHzNFU照射豚鼠耳蜗 6h后 8h能引起不同节段基底膜毛细胞SDH酶活性降低 ,其中外毛细胞较内毛细胞SDH酶活性降低更甚。照射后 8h组较照射后 30min组SDH酶活性有明显恢复。结论不同频率NFU超声照射耳蜗达一定剂量可以引起不同部位基底膜毛细胞的病理性缺氧改变 ,而这种缺氧病理改变在一定暴露剂量下是可逆或部分可逆的。提示耳蜗毛细胞可能与超声感受有关 ,其中外毛细胞可能起更为重要的作用 。

Objective To study the enzyme histochemistry changes of non focused ultrasound (NFU) irradiating the cochlea in guinea pigs. Methods After 30 minutes or 8 hours of 2 5 MHz?8 MHz NFU irradiating the cochlea in guinea pigs (70 ears) for 6 hours, the SDH activity of the hair cells of the cochlea was observed Results The non focused ultrasound (2 5 MHz or 8 MHz) irradiation for 6 hours has lad to enervation of the activity of SDH in hair cells, especially in outer hair cells, in the 0 87±0 20mm areas of the second turn or in the 0 80±0 20mm areas of the first turn, respectively The activity of SDH can be part restorable in the 8 hours groups Conclusion NFU (2 5 MHz?8 MHz) irradiating the cochlea for 6 hours can cause pathological changes in the hair cells of in different areas of cochlear Moreover, the pathological changes could be restorable or part restorable in some amounts of NFU irradiation The results suggest that the cochlear hair cell of the different area might be related to ultrasonic perception