CYTOPLASMIC REGULATION OF TIGHT-JUNCTION PERMEABILITY - EFFECT OF PLANT CYTOKININS
CYTOPLASMIC REGULATION OF TIGHT-JUNCTION PERMEABILITY - EFFECT OF PLANT CYTOKININS
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DOI：
10.1152/ajpcell.1980.239.3.c75
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发表时间：
1980-01-01
影响因子：
--
通讯作者：
BENEDETTI, EL
中科院分区：
文献类型：
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作者：
BENTZEL, CJ;HAINAU, B;BENEDETTI, EL
如果上皮单层细胞具有调节通过连接的分子流的机制，则可以更好地理解渗漏紧密连接的重要性。为了测试这种可能性，在粘膜暴露于植物细胞分裂素（激动素和玉米素）和其他 2 种微丝活性药物（细胞松弛素 B 和鬼笔环肽）之前、期间和之后，对 Necturus 胆囊（一种代表性渗漏上皮）进行了研究。伴随着微丝的形态变化，细胞分裂素诱导跨上皮电阻和电位差（PD）快速可逆增加，并降低 NaCl 稀释电位，而相对细胞膜电阻的比率没有变化。细胞松弛素 B (0.2-1.2 μM) 和鬼笔环肽 (0.6-12.7 μM) 引起跨上皮电阻和 PD 的类似变化。当通过冷冻断裂研究紧密连接的膜内结构时，细胞分裂素诱导的跨上皮阻力峰值增加与链网状结构的更多紊乱相关，导致紧密连接深度小幅增加，但没有证据表明链从头组装。 Necturus 胆囊紧密连接的渗透性显然受到快速可逆调节，可能受到细胞骨架的控制。
The significance of the leaky tight junction might be understood better if cells of the epithelial monolayer possessed mechanisms to regulate molecular flow through the junction. To test this possibility, Necturus gallbladder, a representative leaky epithelium, was studied before, during and after mucosal exposure to plant cytokinins [kinetin and zeatin] and 2 other microfilament-active drugs, cytochalasin B and phalloidin. Concomitant with morphological changes in microfilaments, cytokinins induced rapid reversible increases in transepithelial resistance and potential difference (PD) and decreases in NaCl dilution potentials, with no change in the ratio of relative cell membrane resistances. Cytochalasin B (0.2-1.2 .mu.M) and phalloidin (0.6-12.7 .mu.M) caused similar changes in transepithelial resistance and PD. When the intramembranous structure of tight junctions was studied by freeze fracture, peak cytokinin-induced increments in transepithelial resistance were associated with more disorder in the strand meshwork resulting in a small increase in tight junction depth, but there was no evidence of de novo strand assembly. Permeability of the tight junction of Necturus gallbladder apparently is subject to rapid reversible modulation, possibly under cytoskeletal control.