Peek W D, Shivers R R, McMillan D B
Cell Tissue Res. 1977 Apr 29;179(4):441-51. doi: 10.1007/BF00219847.
Zonulae occludentes are shown by freeze-fracture to be pleomorphic along the garter snake nephron. In the neck and proximal segments the occluding junctions are moderately complex with frequent discontinuities in their junctional fibrils. Junctional depth and complexity are maximal in the distal and collecting segments and discontinuities in fibrils are absent. Comparison of these results with similar observations on other tissues indicates that the zonulae occludentes in the neck and proximal segments are "intermediate" to "leaky" and that they may be "very light" in the distal and collecting segments. The findings suggest that in the garter snake nephron transepithelial flow of fluid may occur primarily by passive diffusion through the zonulae occludentes in the neck and proximal segments and by cell-mediated osmotic flow in the distal and collecting segments. Gap junctions occur only in the proximal tubule and areprobably involved in low resistance, intercellular movement of ions.
冷冻断裂显示，束状带在束带蛇肾单位中呈多形性。在颈部和近端节段，封闭连接中等复杂，其连接纤维常有间断。连接深度和复杂性在远端和集合节段最大，纤维无间断。将这些结果与对其他组织的类似观察结果进行比较表明，颈部和近端节段的束状带是“中间型”至“渗漏型”，而在远端和集合节段可能是“非常轻微渗漏型”。这些发现表明，在束带蛇肾单位中，液体的跨上皮流动可能主要通过颈部和近端节段的束状带被动扩散以及远端和集合节段的细胞介导渗透流发生。缝隙连接仅出现在近端小管中，可能参与离子的低电阻细胞间移动。
