内耳形态学和生理指标对缺铁性肾虚耳聋大鼠模型的评价作用

目的探讨耳蜗显微结构和生理指标对缺铁性肾虚耳聋大鼠模型的评价作用。方法选用体重30～32 g、无耳疾、听性脑干反应(auditory brainstem response,ABR)阈值正常的1～2周龄SPF级SD大鼠120只,雌雄分养,分为缺铁组80只、正常对照组40只,饲养时间12周;以出现肾虚证和至少一耳ABR阈值≥15 dB,作为判断肾虚耳聋的标准,获得缺铁性肾虚耳聋大鼠22只,从中选取肾虚耳聋大鼠20只,同时以20只正常大鼠作对照。观察耳蜗血管纹、螺旋器等耳蜗显微结构变化,检测ABR阈值以及血红蛋白和血清铁等指标的变化。结果实验组和正常对照大鼠的血红蛋白和血清铁分别为11.80 g/L,4.5μmol/L和45.9 g/L,22.23μmol/L,ABR阈值分别为(30±5)dB和(10±5)dB;实验组血管纹血管明显减少;螺旋器毛细胞听毛有缺失、倒伏现象。结论缺铁性肾虚耳聋大鼠血红蛋白、血清铁和ABR阈值,以及耳蜗血管纹、螺旋器等耳蜗显微结构变化等指标,均较为稳定,是较好的评价指标。

Role of microstructure and physiological indexes of the inner ear in evaluation of the rat models of iron-deficient nephrasthenia deafness

Objective To explore the significance of microstructure of cochlea and some physiological indexes in evaluation of the rat models of iron-deficient nephrasthenia deafness.Methods One hundred and twenty healthy Wister rats at age of 1-2 weeks and weighing 30-32 g,without ear disease and within the normal range of ABR threshold,were included in this study.The rats were randomly divided into experimental group（n=80） and control group（n=40）.The male and female rats were fed separately.Iron-deficient diet was fed to the experimental rats and normal diet was fed to the normal rats,both for 12 weeks.According to the occurrence of nephrasthenia syndrome and ABR ≥15dB in at least one ear,22 rats from the experimental group were diagnosed as nephrasthenia deafness,among which 20 deaf rats were taken as the experimental group,and 20 normal rats as the control group.ABR threshold was tested,hemoglobin and serum iron content were measured,and histological changes of the cholea such as stria vascularis and spiral organ were examined in all the rats of both groups.Result The ABR was（30±5） dB in the experimental group and（10±5）dB in the normal group;the hemoglobin was 11.80 g/L in the experimental group and 4.5 g/L in the normal group;the serum iron was 45.9 μmol/L in the experimental group and 22.23 μmol/L in the normal group,all showing a significant difference between the two groups.In the experimental rat cochleae,the blood vessels of stria vascularis were apparently decreased,and the trichobothria of hair cells were lost or lodging.Conclusions There are quite stable changes of the indexes such as hemoglobin and serum iron,ABR threshold,and the vascular changes in the cochlea stria vascularis and spiral organ in the rat models of iron-deficient nephrasthenia deafness,therefore,they may be good indicators for evaluation of this disease.