摘要
目的评价右美托咪定对豚鼠噪声性听力损伤的影响。方法雄性成年豚鼠24只，3月龄，体重400～500g，采用随机数字表法，将其分为3组（12=8）：右美托咪定组（D组）、噪声性听力损伤组（N组）和右美托咪定＋噪声性听力损伤组（D＋N组）。D组和N＋D组经5min静脉输注右美托咪定负荷量5μg／kg，随后以10μg·kg-1·h-1的速率输注135min；N组给予等容量生理盐水。N组和D＋N组给药20min时进行噪声暴露，输入中心频率4kHz，声压118—122dBSPL的倍频程噪声，持续时间120min。分别于给药前和给药期间每5min测定MAP和耳蜗血流量（COBF），计算COBF变化率。于给药20和140rain时，抽取动脉血样，采用高效液相色谱分析法测定血浆去甲肾上腺素（NE）浓度。分别于给药前、给药结束后1、72h和10d时，测听性脑干反应（ABR）阈。结果与N组相比，D＋N组给药5～10min和30～140min时MAP降低，COBF变化率升高，给药结束后1、72h和10d时ABR阈降低，给药140min时血浆NE浓度降低（P〈0．05）。结论右美托咪定可减轻豚鼠噪声性听力损伤，可能与其抑制交感神经活性，升高COBF有关。
Objective To evaluate the effect of dexmedetomidine on noise-induced hearing loss in guinea pigs. Methods Twenty-four adult male guinea pigs, aged 3 months, weighing 400-500 g, were randomly divided into 3 groups （ n = 8 each） using a random number table： dexmedetomdine group （group D）, noise-induced hear- ing loss group （group N） and dexmedetomidine ＋ noise-induced hearing loss group （group DN）. A loading dose of dexmedetomidine 5 μg/kg was infused over 5 min, followed by 135 min of infusion at a rate of 10μg.kg- 1. h- 1 . The equal volume of normal saline was infused in group N. Groups N and DN were exposed to noise of 4 kHz cen- ter frequency and 118-122 dB SPL for 120 min starting from 20 min of administration. Mean arterial pressure （MAP） and cochlear blood flow （COBF） were recorded before administration and every 5 rain during drug adminis- tration. The changing rate of COBF was calculated. Arterial blood samples were collected for determination of plas- ma concentration of noradrenaline （NE） by high performance liquid chromatography at 20 and 140 min of adminis- tration. Auditory brainstem response （ABR） threshold was recorded before administration and at 1 and 72 h and 10 days after the end of administration. Results Compared with group N, MAP was significantly decreased, the changing rate of COBF was increased at 5-10 min and 30-140 min of administration, ABR threshold was decreased at 1 and 72 h and 10 days after the end of administration, and the plasma concentration of NE was decreased at 140 min of administration in D ＋ N group （ P 〈 0.05）. Conclusion Dexmedetomidine can attenuate noise-induced hearing loss in guinea pigs possibly through inhibiting activation of sympathetic nerves and increasing COBF.
出处
《中华麻醉学杂志》
CAS
CSCD
北大核心
2013年第11期1296-1299,共4页
Chinese Journal of Anesthesiology
关键词
右美托咪啶
听觉丧失
噪声性
Dexmedetomidine
Hearing loss, noise-induced
