同种异体内耳组织免疫后豚鼠内耳形态学变化

目的建立一高阳性率、可供圆窗给药治疗内耳病研究用的自身免疫性内耳病动物模型。方法实验动物为86只豚鼠,其中32只用于制备粗制内耳抗原。其余动物随机分为实验组42只,对照组1、2各6只。将实验组动物腹腔注射环磷酰胺进行预处理,2d后用粗制内耳抗原行皮下多点接种,分别于接种后4、6、8、10、12、14、20d时用光镜观察动物内耳形态学变化,并检测其血清中IgG、IgM、C3、CH50、循环免疫复合物(CIC)水平。对照组1不行任何处理,对照组2不接种内耳抗原,余同试验组。结果接种后豚鼠耳蜗、前庭、内淋巴囊等部位出现以淋巴细胞为主的炎性细胞浸润,尤以前庭阶、鼓阶、螺旋神经节区域及耳蜗底圈等部位为重。接种后4d时,67%动物内耳有炎性细胞浸润;8~12d时,100%动物出现炎性细胞浸润;接种14d后,炎性细胞浸润明显减少。接种6~14d时,内耳尚有血管周围炎、螺旋神经节细胞变性、内淋巴积水等改变。结论将豚鼠采用环磷酰胺预处理及同种异体内耳抗原接种,可建立一高阳性率的自身免疫性内耳病动物模型。

Morphological Change of the Inner Ears in the Animals Inoculated with CIEAg-CFA after Cyclophosphamide Pretreatment

Objective To establish an experimental autoimmune inner ear disease model, which can be high positive and be adopted for study of drug treatment for inner ear disease via round window.Methods 86 guinea pigs were used as experimental animals, and 32 of 86 provided crude inner ear antigens (CIEAg). 2 days after pretreated with cyclophosphamide, the guinea pigs were inoculated intracutaneously at multiple sites with 0.2 ml of an emulsion consisting of equal parts of CIEAg and complete Freund's adjuvant (CFA). In the control group, animals received no injection or only cyclophosphamide and CFA. After 4, 6, 8, 10, 12, 14, 20 days of immunization, IgG, IgM, C3, CH50, and CIC levels in the serums of the experimental animals were detected, and the inner ears stained with hematoxylin and eosin were studied by light microscopy.Results Following pretreatment with cyclophosphamide and primary sensitization with crude inner ear antigen (CIEAg) Freund's complete adjuvant(FCA), many inflammatory cells infiltrated transiently into the cochlea, vestibule, and endolymphatic sac, but not into the kidney, lung, brain or liver. The infiltrated cells were mainly lymphocytes, and commonly observed in scala vestibuli, scala tympani, spiral ganglion cells region, and basal turn. This reaction occurred in 67% of animals on day 4, 93% on day 6, all experimental guinea pigs during day 8 to day 12, and then rapidly reduced. In addition, perivasculitis, degeneration of the spiral ganglion cells, and endolymphatic hydrops could be observed from day 6 to day 14. The control animals showed no cellular reaction in the inner ear. Compared with normal control, the IgG, IgM, C3, CH50, or CIC levels in the serums of the experimental animals had no evident change.Conclusion Our results suggested that a possibly ideal model of autoimmune inner ear disease for drug treatment of inner ear disease via round window can be established by a single inoculation of CIEAg-CFA emulsion after pretreatment with cyclophosphamide in guinea pig.