低能量超声照射对豚鼠耳蜗血管纹的影响

Enzyme histochemistry study of stria vascularis of the cochlea in guinea pigs after ultrasound irradiation

目的探讨低能量超声照射豚鼠耳蜗后血管纹的酶组织化学变化。方法以A型脉冲超声波诊断仪为超声发射器,分别以2.5mHz、8.0mHz超声照射豚鼠耳蜗6.0小时后间隔0.5小时、8.0小时,行豚鼠耳蜗血管纹铺片观察琥珀酸脱氢酶(succinate dehydrogenase,SDH)组织化学观察。以Kruskal and Wallis法对血管纹琥珀酸脱氢酶活性(吸光度A值)行统计学处理。结果2.5mHz、8.0mHz超声照射豚鼠耳蜗6.0小时后间隔0.5小时、8.0小时,不同部位耳蜗血管纹SDH酶吸光度A值降低,且照射后8.0小时组较照射后0.5小时组SDH酶吸光度A值有明显升高,这种变化与耳蜗毛细胞SDH酶吸光度A值降低区域大体相对应。结论不同频率低能量超声照射豚鼠耳蜗达一定剂量可引起耳蜗血管纹不同部位SDH酶活性降低,这种变化在一定照射剂量下是可逆或部分可逆的。提示暴露低能量超声达一定剂量可引起耳蜗一定程度的病理改变。

OBJECTIVE To study the enzyme changes of stria vascularis of the cochlea in guinea pigs after ultrasound irradiation. METHODS After 30 minutes or 8 hours of 2.5 mHz, 8.0mHz ultrasound irradiating the cochlea of guinea pigs（45 ears）for 6 hours, the SDH（succinate dehydrogenase） activity of the stria vascularis was observed. RESULTS The ultrasound irradiation for 6 hours had led to enervation of the activity of SDH of the stria vascularis in the （0.91±0.22）mm ranges of the second turn or （0.97±0.26）mm ranges of the first turn, respectively. The A value of SDH of the stria vascularis was higher in the group of 8 hours than the group of 30 minutes after ultrasound irradiation. CONCLUSION Ultrasound（2.5mHz、 8.0mHz ）irradiation the cochlea for 6 hours can cause pathological changes in the stria vascularis of different areas. Moreover, the pathological changes were restorable or part restorable in some amount after ultrasound irradiation.