大鼠膜迷路积水模型的建立及评定

Establishment and Evaluation of A Rat Model of Membranous Labyrinthine Hydrops

目的通过腹腔注射醋酸去氨加压素(DDAVP)探讨建立大鼠膜迷路积水模型的可行性。方法选取30只健康SD大鼠,随机分为正常组、对照组及实验组,不同时间节点分别给予不同剂量的DDAVP及生理盐水腹腔注射,17天后观察大鼠行为学变化,听觉脑干诱发电位(ABR)检测听力的变化,HE染色观察耳蜗形态结构的变化,耳蜗中阶(即蜗管)横截面积(SM)与中阶和前庭阶横截面积(SM+SV)之和的比值的变化。结果实验组大鼠出现平衡障碍,ABRⅡ波阈值升高(P=0.000<0.05);且Ⅱ波(P=0.004<0.05)、Ⅴ波的潜伏期(P=0.000<0.05)及Ⅲ~Ⅴ波间期(P=0.006<0.05)明显延长。HE染色提示前庭膜向前庭阶膨隆或断裂,SM与SM+SV比值增大(P=0.000<0.05)。结论腹腔注射DDAVP可以诱导大鼠内耳膜迷路积水,成功建立膜迷路积水动物模型。

Objective To establish a model of membranous labyrinthine hydrops in rats by intraperitoneal injection of DDAVP.Methods Healthy SD rats(n=30)were randomly divided into a normal group,a control group and a study group to receive different doses of intraperitoneal DDAVP or saline at various time points.Behavioral changes after 17 days,auditory brainstem response(ABR)threshold changes,morphology changes of the cochlea,including the ratio between cross-section area of the scala media(SM)and that of the SM and scala vestibuli(SM+SV),were recorded and compared across the groups.Results Rats in the study groups showed behaviors consistent with balance disorders,with elevated thresholds for ABR waveⅡ(P<0.05),delayed wavesⅡandⅤlatencies(P<0.05)and waveⅢ-Ⅴinter-latencies(P<0.05),as well as vestibular membrane expansion or rupture toward the SV and increased SM to SM+SV cross-section area ratios(P<0.05),as compared to those in the control and normal groups.Conclusion Intraperitoneal injection of DDAVP can induce inner ear labyrinthine hydrops in rats as an animal model for studying membranous labyrinthine hydrops.