摘要
目的研究尼莫地平对内耳缺血/再灌注后豚鼠耳蜗血迷路屏障通透性的影响。方法随机将32只豚鼠分为4组,每组8只,分别为缺血用药组、缺血对照组、再灌注用药组、再灌注对照组。采用小脑前下动脉FeCl3诱导血栓形成制备耳蜗缺血豚鼠模型,缺血1小时后再经股静脉给予尿激酶溶解血栓制备再灌注模型,分别于缺血后早期及再灌注后静脉注射尼莫地平,各对照组以等量生理盐水代替尼莫地平注射。采用激光多普勒血流测量仪监测耳蜗血流量(cochlear bloodflow,CoBF),测量实验前后豚鼠听性脑干反应(ABR)波Ⅲ反应阈值;分别在股静脉推注伊文思蓝2小时后采用荧光定量检测其血迷路屏障通透性变化。结果豚鼠耳蜗发生缺血后早期应用尼莫地平组与缺血对照组伊文思蓝通过血迷路屏障的平均量分别为每只0.245±0.108和0.442±0.153μg,差异有统计学意义(P<0.05);耳蜗发生缺血再灌注后应用尼莫地平组与再灌注对照组,伊文思蓝通过血迷路屏障的平均量分别为每只0.963±0.261和0.620±0.148μg,差异有统计学意义(P<0.05)。结论在内耳缺血早期使用尼莫地平,能减轻血迷路屏障的损伤;但在缺血再灌注后使用尼莫地平,则加重血迷路屏障的损伤,使其通透性增加。
Objective To investigate the effect of intravenous application of nimodipine on blood- labyrinth barrier permeability following cochlear ischemia/reperfusion injury in guinea pigs. Methods The guinea pigs were randomly divided into four groups： nimodipine injection ischemia group （group A）, saline injection ischemia group （group B ）, nimodipine injection reperfusion group （group C）, and saline injection reperfusion group （group D）. Thrombus formation upon the anterior inferior cerebral artery （AICA） induced by Fecl3 was used to develop the cochlear ischemia model in guinea pigs. Reperfusion was performed 1 hour after ischemia by intravenously injected Urokinase （UK）. Nimedipine was intravenously injected in the early period of ischemia and after reperfusion. In saline groups, instead of nimodipine, saline injection was applied accordingly. The cochlear blood flow （CoBF） was monitored continuously with laser Doppler flowmeter. Threshold of auditory brainstem response （ABR） was measured before and after every experiment. The Evan＇ s blue （EB） was intravenously injected at 2 h before the end of experiment in every group. The permeability of blood - labyrinth barrier was observed by the EB fluorescence quantitative method. Results Amount of EB passing through the blood - labyrinth barrier was （ 0.245 ± 0.108）μg per guinea pig in group A, which was obviously decreased （P〈 0.05） as compared with group B（0.442 ± 0. 153）μg per guinea pig. Amount of EB passing through the blood - labyrinth barrier was（0.963 ± 0.261）μg per guinea pig in group C, which was obviously increased （ P 〈 0.05） as compared with group D（0.620 ± 0.148）μg per guinea pig.Conclusion Intravenous application of nimodipine in the early period of cochlear ischemia can alleviate the blood- labyrinth barrier damage and decrease its pemaeability. Intravenous application of nimodipine following cochlear reperfusion can accelerate the blood - labyrinth barrier damage and increase its pemaeability.
出处
《听力学及言语疾病杂志》
CAS
CSCD
2006年第4期292-294,308,共4页
Journal of Audiology and Speech Pathology
