空气负离子和噪声对豚鼠耳蜗血流的影响

目的：观察空气负离子和噪声对耳蜗血流的影响及探索其机理。方法：２４只雄性豚鼠随机分为噪声暴露组（１１８ｄＢＳＰＬ３０ｍｉｎ），空气负离子暴露组（１．１６ｘ１０６／ｃｍ３３０ｍｉｎ），空气负离子和噪声暴露组（按上两组方法先后各暴露３０ｍｉｎ）和对照组共四组。采用激光多普勒血流计（ＬＤＦ－３型）在噪声暴露和吸入空气负离子前后不同时间，测量耳蜗底回血流量，输出以电压值数字显示，并输入微机进行信息处理。结果：单一吸入空气负离子可使耳蜗血流量明显增加；单一噪声暴露，则可使耳蜗血流量明显减少，６０分钟后恢复到暴露前水平；噪声暴露前预先吸入空气负离子可改善噪声对耳蜗血流量的影响，并在１０分钟后即恢复到实验前水平。结论：预防性吸入空气负离子可增加耳蜗血流量，改善微循环，因而对保护噪声性耳蜗损伤是有益的。

Effects of negative air ions and noise on cochlear blood flow in gulnea pigs

Aim:To observe the effects of negative air ions and noise on cochlear blood flow and verify the protective mechanism of negative air ions against acoustic trauma.Methods:24 male guinea pigs were equally divided into four groups. Group 1 was exposed to 118 dB SPL white noise for 30 min.Group 2 inhalated the air containing negative air ions with a concentration of 1.16x 106/cm3 for 30 min.Group 3 inhalated the air containing negative air ions with a concentration of 1. 16x 106/cm3 for 30 min first,and then exposed to 118 dB SPL white noise for 30 min.Group 4 was the control.The blood flow in the basal turn of cochlea in each animal was measured before and 1,10,20,30,60 and 90 min after the begining of experiment procedure using a laser DOppler flowmeter(LDF-3)with the laser probe( 0. 9 mm diameter)contacting the bony surface of the lateral wall in the basal turn of the cochlea.The out-put values were digitally displayed in voltage and treated by computer averaging technique.Results:Cochlear blood flow significantly increased after Inhalation of negative air ions for 30 min. An exposure to a 118 dB SPL white noise for 30 min caused a significant decrease in blood flow,but then recovered to pre-exposure level after 60 min. Prophylactic inhalation of negative air ions before noise exposure im-proved the microcirculation in cochlea during the noise exposure,and the cochlear blood flow recovered to pre-experiment level in 10 min. Conclusion:Prophylactic inhalation of negative air ions can increase the cochlear blood flow and promote microcirculation thus protecting the cochlea from acoustic trauma.