Hirsch M, Montcourrier P, Renard G
Albrecht Von Graefes Arch Klin Exp Ophthalmol. 1977 Sep 28;203(3-4):169-79. doi: 10.1007/BF00409823.
There is in the ciliary epithelium a barrier which prevents the passage of plasma proteins into the posterior chamber of the eye. The anatomical site of this blood-aqueous barrier is at the zonulae occludentes (tight junctions) located between the lateral plasma-membranes of the nonpigmented epithelial cells. Using the freeze-fracture technique we have studied these junctions in the pars plicata. As in many epithelia, they are formed by an anastomosing network of ridges on the fracture PF face and by a complementary set of furrows on the fracture EF face of plasma membranes. Features of these junctions are the presence of frequent parallel and closely associated double or triple ridges, and a few small gap junctions, associated with tight junctional elements of the zonulae occludentes. We also show that the number of junctional strands (ridges and furrows from apex to base) varies from a few strands to about 15, according to their position around the nonpigmented epithelial cells. These observations suggest that the rabbit's ciliary epithelium is to be classified among the 'tight' or 'very tight' epithelia (Claude and Goodenough, 1973). After paracentesis, we observed no breakdown of the zonulae occludentes. This supports the hypothesis that the site of leakage of the plasma proteins is elsewhere than ciliary epithelium.
睫状体上皮中存在一种屏障，可阻止血浆蛋白进入眼后房。这种血-房水屏障的解剖部位位于无色素上皮细胞外侧质膜之间的紧密连接（闭锁小带）处。我们利用冷冻断裂技术研究了睫状突中的这些连接。与许多上皮组织一样，它们由质膜断裂面PF上吻合的嵴网络以及断裂面EF上互补的沟组成。这些连接的特征是存在频繁的平行且紧密相连的双嵴或三嵴，以及一些与闭锁小带紧密连接元件相关的小缝隙连接。我们还表明，连接链（从顶端到底部的嵴和沟）的数量根据其在无色素上皮细胞周围的位置，从几条到约15条不等。这些观察结果表明，兔的睫状体上皮应归类为“紧密”或“非常紧密”的上皮组织（克劳德和古德诺夫，1973年）。穿刺后，我们未观察到闭锁小带的破坏。这支持了血浆蛋白渗漏部位在睫状体上皮以外的其他地方这一假说。
