Robenek H, Themann H, Ott K
Eur J Cell Biol. 1979 Oct;20(1):62-70.
Application of carbon tetrachloride produced a progressive proliferation of tight junctions in the rat liver. This system proved to be rapid and highly reproducable and affords the opportunity for tracing the fate of tight junctions in freeze-fracture replicas, facilitating investigations on their formation and function. Beginning on day one carbon tetrachloride treatments resulted in the progressive loosening and fragmentation of the junctional meshwork. After three to four days the membrane outside the zonulae occludentes was extensively filled with proliferated discrete junctional elements often forming complex configurations. From the fifth day on the zonulae occludentes were restricted again predominantly around the bile canaliculus margins. But the junctional meshwork of the zonulae occludentes remained loosened in comparison to those in the control rats. It could be shown that tight junction proliferation on the lateral surface of the plasmalemma occurred both through de novo formation from discrete centers of growth by addition of intramembranous particles and through reorganization of preexistent junctional strands of the fragmented zonulae occludentes bodies. Whereas the large gap junctions close associated with the zonulae occludentes remained more or less unaffected during the experiments, small gap junctions increased in number after five days and were located at the margin or in the tight junction domain. It is assumed that the degeneration of the tight junctions served as a pool for intramembranous particles which form the gap junctions. The results of these observations are discussed in relation to those obtained in other systems.
四氯化碳的应用导致大鼠肝脏紧密连接逐渐增殖。该系统被证明是快速且高度可重复的，并为追踪冷冻断裂复制品中紧密连接的命运提供了机会，有助于对其形成和功能进行研究。从第一天开始，四氯化碳处理导致连接网络逐渐松弛和断裂。三到四天后，紧密连接带外侧的膜被大量增殖的离散连接元件广泛填充，这些元件常常形成复杂的结构。从第五天开始，紧密连接带再次主要局限于胆小管边缘周围。但与对照大鼠相比，紧密连接带的连接网络仍然松弛。可以证明，质膜侧面的紧密连接增殖既通过从离散生长中心从头形成，即通过添加膜内颗粒，也通过断裂的紧密连接带体的预先存在的连接链的重组。而与紧密连接带紧密相关的大型间隙连接在实验过程中或多或少未受影响，小型间隙连接在五天后数量增加，并位于边缘或紧密连接区域内。据推测，紧密连接的退化充当了形成间隙连接的膜内颗粒的来源。这些观察结果与在其他系统中获得的结果相关进行了讨论。
