尼福地平对豚鼠耳蜗功能和噪声性听力损失的影响  

Effect of nifedipine, a calcium channel blocker, on cochlear function and noise-induced hearing loss in guinea pigs

作　　者：刘军[1] 孙勍[1] 韩冰[1] 孙建和[1] 于宁[1] 李兴启[1] 

机构地区：[1]解放军总医院耳鼻咽喉头颈外科,耳鼻咽喉科研究所,北京100853

出　　处：《中国耳鼻咽喉头颈外科》2006年第4期232-236,共5页Chinese Archives of Otolaryngology-Head and Neck Surgery

基　　金：国家自然科学基金资助项目(39870797)

摘　　要：目的观察L-型钙通道阻滞药尼福地平对耳蜗功能的影响及其对噪声性听力损失(noise-inducedhearingloss,NIHL)的保护作用。方法健康杂种豚鼠40只,随机分为四组:人工外淋巴液组;尼福地平组;人工外淋巴液加噪声暴露组;尼福地平加噪声暴露组。四组动物按分组条件分别行耳蜗外淋巴液灌流,给予噪声暴露或不给噪声暴露,从圆窗记录复合动作电位(compoundactionpotential,CAP)阈值和微音电位(cochlearmicrophonics,CM)幅值,上述两个指标在灌流前和灌流120分钟各记录一次。结果人工外淋巴液组灌流前后的CAP阈值和CM幅值无显著差异(P>0.05);尼福地平组灌流后CAP阈值升高、CM幅值下降(P<0.05)。尼福地平加噪声暴露组及人工外淋巴液加噪声暴露组,噪声暴露后较噪声暴露前CAP阈值升高和CM幅值下降(P<0.05),CAP阈值升高和CM幅值降低程度,前组比后组低(P<0.01)。结论尼福地平可能作用于耳蜗毛细胞上的L-型钙通道,对耳蜗功能有抑制作用并对NIHL有部分保护作用。OBJECTIVE To investigate the potential effects of nifedipine,a L-type calcium channel blocker, on cochlear function,and its protective effectst on noise-induced hearing Ioss（NIHL）in guinea pigs. METHODS Forty healthy hybrid guinea pigs were divided randomly into four groups. The perilymph spaces of guinea pigs cochlea were perfused with artificial perilymph solutions containing no or 0.5μmol/L nefidipine with or without noise exposure for two hours, respectively. The groups were thus： ①perfused with artificial perilymph solution（APS）;② perfused with artificial perilymph solution containing 0.5μmol/L nifedipine（NIF）;③perfused with artificial perilymph solution and exposed to noise（APS＋noise）; ④perfused with artificial perilymph solutions containing 0.5μmol/L nifedipine and exposed to noise（NIF ＋noise）. Compound action potential（CAP）and cochlear microphonics（CM）were recorded from the round windows of guinea pigs before and 120 minutes after perfusion. RESULTS There was no significant difference in CAP threshold and CM amplitudes before and after perfusion in the APS group（P〉0.05）. A rise in CAP threshold and reduction in CM amplitude after perfusion were found in the other three groups（P〈0.01 ）. The increase in CAP thresholds after perfusion of these three groups were 28dB SPL,43.5 dB SPL,and 20 dB SPL,respectively. The reduction of CM amplitudes in the same three groups were 70.3 %,37.1%,21.1 %, respectively. CONCLUSION We conclude that nifedipine resulted in a suppression of cochlear function and might have a partial prophylactic effect against NIHL. The above evidences could be explained by the block of L-type calcium channels by nifedipine in cochlear hair cells.

关 键 词：尼福地平 听觉丧失 噪声性 耳蜗微音电位 钙通道 

分 类 号：R764[医药卫生—耳鼻咽喉科]