Prescott A R, Stewart S, Duncan G, Gowing R, Warn R M
School of Biological Sciences, University of East Anglia, Norwich, U.K.
Exp Eye Res. 1991 Jan;52(1):83-92. doi: 10.1016/0014-4835(91)90131-w.
The isolated frog lens epithelium can be maintained with its cell shape, cytoskeletal organization and membrane electrophysiological characteristics intact for more than 24 hr. Perifusion with the permeant oxidant diamide (1 mM) led to drastic, but reversible, changes in all the above parameters. After a 20 min exposure to diamide, the regular polygonal arrangement of the epithelial cells become increasingly disrupted as the cells reorganized and a 'rosette' pattern formed. The cells at the edges of the rosette pulled apart from one another while those in the centre maintained a relatively normal appearance. Blebs formed on the apical surface of all of the cells on prolonged exposure and the internal structure was also found to be severely disrupted. The cytoplasm became granular, vacuolated and the nucleus had a banded, non-homogeneous appearance. Phalloidin staining of F-actin microfilaments revealed that there was a general disruption of organization, with actin losing its association with the membrane. The microtubule array, organized around the centrosome, was also severely disrupted although microtubules were still discernible in most cells. During exposure to diamide the membrane potential depolarized and both electrical and dye coupling, which are normally extremely efficient in these cells, were disturbed. If the epithelium was exposed to 1 mM diamide for more than 45 min then all of the above changes were irreversible and cell death followed. If exposure was restricted to less than 30 min, then all of the above changes occurred and, in fact, progressed for over 1 hr; but if the epithelium was perifused for a further 20 hr in control medium, then most of the changes were reversible.
分离出的青蛙晶状体上皮细胞能够保持其细胞形态、细胞骨架组织和膜电生理特性完整超过24小时。用渗透性氧化剂二酰胺（1 mM）进行灌流会导致上述所有参数发生剧烈但可逆的变化。暴露于二酰胺20分钟后，随着细胞重新组织并形成“玫瑰花结”模式，上皮细胞规则的多边形排列变得越来越紊乱。玫瑰花结边缘的细胞彼此拉开，而中心的细胞保持相对正常的外观。长时间暴露后，所有细胞的顶端表面都形成了泡状突起，并且内部结构也被发现严重破坏。细胞质变得颗粒状、空泡化，细胞核呈现带状、不均匀的外观。用鬼笔环肽对F-肌动蛋白微丝进行染色显示，其组织普遍受到破坏，肌动蛋白与膜失去了联系。围绕中心体组织的微管阵列也受到严重破坏，尽管在大多数细胞中仍可辨别出微管。在暴露于二酰胺期间，膜电位去极化，并且在这些细胞中通常极其有效的电耦合和染料耦合都受到干扰。如果上皮细胞暴露于1 mM二酰胺超过45分钟，那么上述所有变化都是不可逆的，随后细胞死亡。如果暴露时间限制在30分钟以内，那么上述所有变化都会发生，并且实际上会持续超过1小时；但是如果上皮细胞在对照培养基中再灌流20小时，那么大多数变化是可逆的。
