模拟微重力条件下大鼠眼压及睫状体上皮的变化

Changes of Intraocular Pressure and Ciliary Body Structure in Rats Under Simulated Microgravity Conditions

目的观察在尾悬吊模拟微重力状态下,大鼠眼压波动的情况及睫状体上皮结构的变化。方法选取SD大鼠30只,利用尾悬吊法建立模拟微重力状态大鼠模型。其中10只大鼠持续尾悬吊状态,在悬吊前、悬吊后1周、2周、3周、4周、8周及12周时麻醉后测量眼压。8只为对照组,与眼压组同时测量眼压。12只大鼠平均分为4组,分别在悬吊前、悬吊4周、8周、12周麻醉后摘取眼球,观察睫状体上皮细胞的显微结构及超微结构。结果持续悬吊状态下,大鼠眼压呈现轻度下降趋势,差异显著,具有统计学意义(P=0.0000),组间比较显示眼压下降最明显的为悬吊后3周后(P<0.05)。睫状体上皮细胞显微结构观察发现,随着悬吊时间的延长,睫状体结构逐步紊乱,上皮细胞数量明显减少,并可见部分上皮细胞脱落;超微结构观察发现,随着悬吊时间的延长,睫状体上皮细胞肿胀,细胞间隙增宽,细胞脱落,细胞核水肿,染色体边集,线粒体肿胀崩解,内质网崩解。结论在尾悬吊模拟微重力条件下,大鼠眼压会呈现轻微下降的趋势。睫状体上皮细胞会出现的显微结构及超微结构变化。

Objective To observe the changes of intraocular pressure and ciliary body structure in rats under tail-suspension simulated microgravity.Methods Twenty-seven SD rats were selected and the tail suspension method was used to establish the simulated microgravity rat model.Intraocular pressure was measured before,1 week,2 weeks,3 weeks,4 weeks,8 weeks and 12 weeks after suspension.The IOP of 8 rats was measured simultaneously with IOP group.The eyes of 12 rats were taken before,4 weeks,8 weeks,and 12 weeks aftersuspension,to observe the microstructure and ultrastructure of the ciliary body.Results The intraocular pressure of the rats gradually decreased,and the difference was statisticallysignificant(P=0.0000)after suspension.Comparison between groups showed that the most significant intraocular pressure decrease was 3 weeks after suspension(P<0.05).Light microscopy showed that with the extension of suspension time,the structure of ciliary body was gradually disordered,the number of epithelial cells decreased,and some epithelial cells were shed.Electron microscopy showed that with the extension ofsuspension time,the ciliary epithelial cells were swollen,the cell space was widened,the cells were shed,the nucleus was swollen,the chromosome edge set,the mitochondria were swollen and disintegrated,and the endoplasmic reticulum was disintegrated.Conclusions Under the simulated microgravity condition with tail suspension,the intraocular pressure of rats tended to decrease gradually.The ciliary epithelium has obvious microstructure and ultrastructure damage.