Uga S, Nishigori H, Ishikawa S
Department of Ophthalmology, School of Medicine, Kitasato University, Kanagawa, Japan.
Graefes Arch Clin Exp Ophthalmol. 1994 Jul;232(7):415-20. doi: 10.1007/BF00186583.
Nishigori et al. reported a transient cataract model after administering glucocorticoid to a 15-day-old chick. Biochemically, the mechanism of onset of this cataract was though to be related to damage caused by the formation of oxidative stresses and by a protein-water phase separation. There appear to be no reports on changes in the fine structure. After hydrocortisone succinate sodium was administered to 15-day-old chick embryos, the lenses were removed at 12, 24, 30, 48, 72 and 96 h and put in 4% glutaraldehyde. The specimens were examined by light, transmission and scanning electron microscopy. Twelve to 24 h after administration to chick embryos, lens fibers containing electron-dense cytoplasm began to appear in the bow area of the equator and were still present thereafter. Thirty to 48 h after administration, numerous vacuoles of varying sizes began to appear in the lens in sites corresponding to the opaque region. These vacuoles, ranging from 2 to 8 microns in diameter, were distributed in the intercellular spaces between the lens fibers. The vacuoles had disappeared by 96 h after administration, but during that period, the height of the epithelial cells in the equatorial region and the elongation of the equatorial lens fibers had become irregular. Transient opacity was due to the presence of vacuoles of various sizes, occurring in the intercellular space between the lens fibers around the lens nucleus. Moreover, the effect of glucocorticoid administration was noted in the lens epithelium and the lens fibers in the equatorial region.
西五里等报道了给15日龄雏鸡施用糖皮质激素后建立的短暂性白内障模型。从生化角度来看，这种白内障的发病机制被认为与氧化应激形成和蛋白质 - 水相分离所造成的损伤有关。目前似乎尚无关于精细结构变化的报道。给15日龄鸡胚施用琥珀酸氢化可的松钠后，分别在12、24、30、48、72和96小时取出晶状体，并置于4%戊二醛中。通过光学显微镜、透射电子显微镜和扫描电子显微镜对标本进行检查。给鸡胚施用药物后12至24小时，赤道区弓状区域开始出现含有电子致密细胞质的晶状体纤维，此后一直存在。施用药物后30至48小时，晶状体中与不透明区域相对应的部位开始出现大量大小不一的空泡。这些空泡直径在2至8微米之间，分布在晶状体纤维之间的细胞间隙中。施用药物后96小时空泡消失，但在此期间，赤道区上皮细胞的高度和赤道区晶状体纤维的伸长变得不规则。短暂性混浊是由于在晶状体核周围的晶状体纤维之间的细胞间隙中出现了各种大小的空泡。此外，在晶状体上皮和赤道区的晶状体纤维中也观察到了施用糖皮质激素的作用。
