尾静脉注射碘酸钠对小鼠视网膜形态结构变化的影响

目的　探讨尾静脉注射碘酸钠（NaIO₃）对小鼠视网膜形态结构的影响。方法　36只昆明小鼠分为4组:对照组、损伤3 d组、损伤7 d组、损伤14 d组。对照组不作任何处理，各损伤组小鼠经尾静脉单剂量注射NaIO₃（35 mg?kg^-1）。在NaIO₃损伤3 d、7 d、14 d后取材，进行视网膜组织铺片和组织切片。利用HE染色、NeuN免疫组织化学染色及 Opn1mw、GFAP、Iba1免疫荧光染色，检测NaIO₃注射后不同时间小鼠视网膜形态结构的改变。结果　HE染色结果显示，损伤3 d后外核层每10 μm长度细胞数由正常水平（31.97±2.27）个下降至（26.21±0.83）个，差异有统计学意义（P<0.05）；损伤7 d后内核层每10 μm长度细胞数由正常水平（12.33±0.16）个下降至（11.39±0.43）个，差异有统计学意义（P<0.05）。NeuN染色结果显示，损伤14 d后视网膜神经节细胞层每100 μm长度视网膜神经节细胞数由正常水平（14.92±1.74）个下降至（11.25±0.09）个，差异有统计学意义（P<0.05）。GFAP染色结果显示，损伤3 d组每200 μm × 200 μm 范围内活化的Müller细胞数由对照组的（16.96±0.85）个增加至（20.42±1.64）个，差异也有统计学意义（P<0.05）。Opn1mw、Iba1染色结果显示，损伤后视网膜视锥细胞外节段变薄、小胶质细胞数增加。结论　尾静脉注射NaIO₃会引起小鼠视网膜形态结构不可逆的损伤，且该损伤具有时间依赖性。

Effect of sodium iodate on morphological and structural changes of retina in mice

Objective To investigate the effect of the sodium iodate(NaIO3)on retinal morphology injected into mice via the tail vein.Methods Totally 36 Kunming mice were divided into 4 groupscontrol group,NaIO3-injected on day 3 group,day 7 group,day 14 group.The control group received no treatment,and the NaIO3-injected group mice received NaIO3(35 mg·kg-1)in a single dose via the tail vein.After 3,7,and 14 days,retinal tissue was laid and sectioned.Retinal morphology was assessed at different NaIO3-injected time points via HE staining,NeuN immunohistochemical staining,Opn1mw,GFAP and Iba1 immunofluorescence staining.Results HE results shown that,after NaIO3-injected 3 days,the cells number per 10μm in outer nuclear layer were reduced from(31.97±2.27)to(26.21±0.83)(P<0.05);and after NaIO3-injected 7 days,the cells number per 10μm in inner nuclear layer were reduced from(12.33±0.16)to(11.39±0.43)(P<0.05).NeuN staining shown that,after NaIO3-injected 14 days,the cells number of retinal ganglion cell per 100μm were reduced from(14.92±1.74)to(11.25±0.09)(P<0.05).GFAP staining showed that,after NaIO3-injected 3 days,the number of GFAP-positive astrocytes per 200μm×200μm were increased from(16.96±0.85)to(20.42±1.64)(P<0.05).According to the staining results of Opn1mw and Iba1,the outer segments of cones became thinner,as well as the number of microglia cell was significantly increased after NaIO3-injected.Conclusion A single dose(35 mg·kg-1)of NaIO3 can cause irreversible,time-dependent morphological and structural damage of the retina in mice.