Abstract: Objective To compare the changes of ocular structure and function in albino rats and nonalbino rats after simulated long-term microgravity exposure, and to improve and supplement the animal model of ocular injury caused by simulated long-term microgravity exposure. Method Male SD and BN rats, each 12, were randomly divided into control group (NS and NB ) and model group ( MS and MB ) . 30 ° headed-down tail suspension for 8 weeks was used to simulate microgravity for model group. At the end of the model, electroretinogram (ERG) and visual evoked potential (VEP) were used to detect the function of retina. The morphology of retina was observed by HE staining, and the changes of blood vessels in fundus were observed by small animal fundus imaging system. Result After 8 weeks of simulated weightless suspension, the structure and function of the retina of Sprague-Dawley rats ( SD, albino rats) changed significantly, and the amplitude of ERG dark adaptation 3. 0 response decreased significantly (P< 0. 01) , the peak time of P1 wave of VEP was significantly prolonged (P<0. 01) , HE staining showed thinning of the outer nuclear layer (P<0. 01) , increased blood flow of choroidal vessels was observed in the fundus, while there were no significant changes in retinal structure and function in Brown-Norway rats (BN, non-albino rats) after suspension. Conclusion Albino rats exhibit heightened vulnerability to ocular damage when exposed to prolonged simulated weightlessness, thus warranting investigation into the role of melanin synthesis-associated proteins within the retinal pigment epithelium as a potential means of mitigating retinal degeneration induced by prolonged simulated weightlessness.

Key words: albino rats, non-albino rats, SD rats, BN rats, simulated weightlessness, degeneration of the retina

摘要： 目的 比较白化鼠与非白化鼠在长期模拟失重后眼部结构与功能的改变,完善和补充长期微重力暴露所致眼部损伤疾病动物模型构建方法。 方法 将正常雄性 Sprague-Dawley( SD) 大鼠(白化鼠) 和 Brown-Norway( BN) 大鼠(非白化鼠)各 12 只随机分为 SD 正常对照组(NS) 、BN 正常对照组(NB) 、SD 模型组(MS)和 BN 模型组(MB) ,每组 6 只,模型组采取 30°头低位尾悬吊 8 周模拟长期失重,在造模结束后利用视网膜电流图(ERG)和视觉诱发电位(VEP)检测大鼠的视觉功能,石蜡切片 HE 染色观察视网膜形态,同时通过小动物眼底成像系统观察大鼠眼底血管改变情况。 结果 在 8 周尾吊模拟失重后,MS 组与 NS 组相比,暗适应 3. 0 ERG 反应振幅明显下降(P<0. 01) ,VEP的 P2 波峰时值明显延长(P<0. 01) ,HE 染色显示外核层变薄( P<0. 01) ,眼底可见脉络膜血管血流增多,而 MB 组与 NB 组相比,视网膜结构与功能均无明显变化。 结论 与非白化大鼠相比,白化大鼠在长期模拟失重情况下更容易出现眼部损伤,视网膜色素上皮细胞中黑色素合成相关蛋白可能是研究对抗模拟长期失重导致视网膜退行性变的重要分子。

关键词: 白化鼠, 非白化鼠, SD 大鼠, BN 大鼠, 模拟失重, 视网膜退行性病变