中文摘要：

目的 观察短期铅暴露对成年豚鼠听性脑干反应（auditory brainstem response,ABR）的影响。方法将24只听力正常的成年黑目花色豚鼠随机分为4组（A、B、C、D组,每组6只）,分别用含醋酸铅浓度为2 mmol/L的铅水进行喂养0、15、30及60 d,所有动物均在实验结束时测试双耳ABR并断头采血检测血铅浓度。结果 各组动物的血铅浓度分别为A组（58.91±7.76）μg/L、B组（659.00±62.71）μg/L、C组（733.00±68.96）μg/L、D组（701.80±54.75）μg/L。各组动物由click诱发的ABR阈值分别为A组（25.91±3.75）d B SPL、B组（23.57±5.56）d B SPL、C组（26.88±5.94）d B SPL、D组（25.63±5.00）d B SPL,各组动物之间比较,差异无统计学意义（P〉0.05）。在70 d B SPL的click声刺激下,随着铅暴露时间的延长,I波潜伏期出现延长的趋势,但差异无统计学意义（P〉0.05）;30 d及60 d与对照组相比,III波振幅出现减小,其差异具有统计学意义（P〈0.01）。结论 短期铅暴露（2个月内）对成年豚鼠ABR阈值无明显影响,但铅暴露时间超过30 d,从耳蜗传导到中脑的听觉信号强度开始出现下降。

英文摘要：

Objective To investigate the effect of short-term lead exposure on auditory brainstem response （ABR） of adult guinea pigs. Methods 24 adult guinea pigs with normal hearing were randomly divided into 4 groups with equal number （A, B, C, D group, n =6）. They were fed with water containing lead acetate at concentration of 2 mmol/L for0, 15, 30 or 60 days, respectively. Binaural ABR and blood lead concentration were measured at the end of the experiment. Results The blood lead concentrations of group A to D were 58.91 ± 7.76,659.00 ±62.71,733.00 ± 68.96,701.80 ± 54.75 μg/L, respectively. At the click sound stimulus of 70 dB SPL, wave I was delayed with the prolonging of lead exposure duration, but the differences were statistically insignificant （ all P 〉 0.05 ） ; Compared to the control group, the amplitudes of III wave decreased at the 30th day and 60th day, and the differences were both statistically significant （ both P 〈 0. 01 ）. Conclusions Short-term （with duration shorter than 2 months ） lead exposure shows no significant impact on ABR threshold of aduh guinea pigs. However, the auditory signal intensity from the cochlea to the middle brain decreases significantly after lead exposure for more than 30 days.