光化学法诱导豚鼠耳蜗微循环障碍模型

Cochlear microcirculatory disorders induced by photochemical method in guinea pigs

目的通过光化学法建立豚鼠耳蜗微循环障碍模型以及观察血管纹、耳蜗毛细胞形态学变化。方法①将豚鼠随机分成5个组。实验组分成3个组,颈外静脉注入四氯四碘荧光素二钠(rose bengal,RB),用波长为(540±40)nm、光强为(500～600)mW/cm2绿光照射打开的听泡,各组选用不同光照时间诱导耳蜗微循环变化。对照组分2个组,对照Ⅰ组仅颈外静脉注入RB而不行光照;对照Ⅱ组不注入RB而仅行光照耳蜗。②分别对5个组动物行听性脑干反应及形态学检测。结果①每个实验组两次ABRⅢ波反应阈差异均有统计学意义(P<0.05);②形态学观察实验组均出现耳蜗微循环障碍的变化,螺旋器以外毛细胞破坏为主。结论采用光化学法可致耳蜗微循环障碍及毛细胞破坏,方法简便,易于实施,重复率高。

OBJECTIVE To set up a model of cochlear microcirculatory disorders in guinea pig with photochemical method and observe the morphological changes of stria vascularis （SV） and hair cells. METHODS Thirty-two guinea pigs were randomly divided into 5 groups. In three experimental groups, photochemical reaction with different illuminating time was used to induce the change of cochlear microcirculation through injecting rose bengal （RB） into the external jugular vein and illuminating the opened tympanic bulla with the green light of 540＋40 nm wavelength and 500-600mW/cm2 intensity. Control group 1 only was injected with RB through the extemal jugular vein without illuminating, and cochlea was only illuminated in control group 2. The auditory brainstem response （ABR） wave HI threshold and morphological observation was applied to 5 animal groups. RESULTS （1）The twice ABR wave Ⅲ threshold had significant statistical differences between experimental groups and control groups （P〈0.05）. （2）Morphological observation： Surface preparation of the spiral ligament showed microcirculatory disorders of SV in the lateral wall of cochlea in three experimental groups. The damage of outer hair cells （OHCs） was more severe and extensive than that of inner hair cells （IHCs）. CONCLUSION Ischemia and thrombosis of the cochlear microcirculation and the damage of hair cells can be induced by photochemical method in guinea pig. This method is simple, rapid, and reproducible.