摘要
目的研究地塞米松对豚鼠内耳缺血再灌注后应用尼莫地平致血迷路屏障损伤的影响。方法随机将豚鼠分为4组:地塞米松预处理再灌注应用尼莫地平组(A组)、再灌注应用尼莫地平及地塞米松组(B组)、再灌注应用尼莫地平组(C组)、再灌注对照组(D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。实验过程中采用激光多普勒血流测量仪监测耳蜗血流量,实验前后测量豚鼠听性脑干反应Ⅲ波反应阈值。分别在股静脉推注伊文思蓝(Evaan'sBlue,EB)2小时后采用荧光定量检测其血迷路屏障通透性变化。结果耳蜗发生再灌注后应用尼莫地平组与再灌注对照组,EB通过血迷路屏障的量分别为每只(0.963±0.261)μg和(0.620±0.148)μg,t检验P<0.05,地塞米松预处理再灌注应用尼莫地平组与再灌注应用尼莫地平及地塞米松组,EB通过血迷路屏障的量分别为每只(0.619±0.212)μg和(0.859±0.228)μg。结论内耳缺血早期使用地塞米松,能减轻血迷路屏障再灌注后尼莫地平引起的急性高灌注所致继发损伤。
OBJECTIVE To investigate the effects of intravenous application of dexamethasone on bloodlabyrinth barrier permeability following nimodipine injection induced cochlear ischemia/reperfusion injury in guinea pigs. METHODS The guinea pigs were randomly divided into 4 groups： dexamethasone injection ischemia and nimodipine injection reperfusion group （group A）, nimodipine and dexamethasone injection reperfusion （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）. Nimodipine was intravenously injected after reperfusion. In saline group, saline injection was applied instead of nimodipine. The blood flow of cochlea （CoBF） was monitored continuously with laser Doppler flowmeter. Threshold of auditory brainstem response （ABR） was measured before and after experiment. The Evan＇s blue （EB） was intravenously injected at 2 hours 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（0.963±0.261）pg per guinea pig in group C, which was obviously increased （P 〈0.05） as compared with that in group D（0.620±0.148）pg. Amount of EB passing through the bloodlabyrinth barrier was（0.619± 0.212）pg per guinea pig in group A,which was obviously decreased （P〈0.05） as compared with that in group C（0.963±0.261）pg. Amount of EB passing through the blood-labyrinth barrier was（0.859±0.228）μg per guinea pig in group B, which was no difference （P 〉0.05） as compared with that in group C（0.963±0.261）μg. CONCLUSION Intravenous application of dexamethasone in the early period of cochlear ischemia could alleviate theblood-labyrinth barrier damage caused by intravenous injection of nimodipine after reperfusion and decrease its permeability.
出处
《中国耳鼻咽喉头颈外科》
北大核心
2006年第7期483-486,共4页
Chinese Archives of Otolaryngology-Head and Neck Surgery
关键词
地塞米松
豚鼠
耳蜗
再灌注损伤
尼莫地平
Dexamethasone
Guinea Pigs
Cochlea
Reperfusion Injury
Nimodipine
