Misfeldt D S, Sanders M J
J Membr Biol. 1981 Mar 15;59(1):13-8. doi: 10.1007/BF01870816.
The pig kidney cell line LLC-PK1 cultured on a collagen coated membrane filter formed a continuous sheet of oriented asymmetrical epithelial cells joined by occluding junctions. A transepithelial electrical potential (PD) and short-circuit current (SCC) were dependent on the presence of Na and sugar in the apical bathing solution. In the presence of 5.5 mM D-glucose, a PD of 2.8 mV. apical surface negative a SCC of 13 microA cm-2 and transepithelial resistance of 211 ohm.cm2 were recorded. The SCC was promptly reduced by the addition of phlorizin to the apical bath but unaffected when placed in the basolateral bath. The effect on SCC of various sugars was compared by the concentrations required for half-maximal SCC: 0.13 mM beta-methyl-D-glucoside, 0.28 mM D-glucose, 0.65 mM alpha-methyl-D-glucoside, 0.77 mM 6-deoxy-D-glucose, 4.8 mM D-galactose, and 29 mM 3-O-methyl-glucose. When [Na] was reduced, the concentration of D-glucose required for half-maximal SCC increase. Isotopically labeled 3H and 14C D-glucose were used to simultaneously determine bidirectional fluxes; a resultant net apical-to-basolateral transport was present and abolished by phlorizin. The transported isotope cochromatographed with labeled D-glucose, indicating negligible metabolism of transported glucose. The pig kidney cell line, LLC-PK1, provides a cell culture model for the investigation of mechanisms of transepithelial glucose transport.
在胶原包被的膜滤器上培养的猪肾细胞系LLC-PK1形成了一层连续的、由紧密连接连接的定向不对称上皮细胞片。跨上皮电势（PD）和短路电流（SCC）取决于顶端浴液中Na和糖的存在。在存在5.5 mM D-葡萄糖的情况下，记录到PD为2.8 mV，顶端表面为负，SCC为13 μA/cm²，跨上皮电阻为211 Ω·cm²。向顶端浴中添加根皮苷会迅速降低SCC，但置于基底外侧浴中时不受影响。通过达到半数最大SCC所需的浓度比较了各种糖对SCC的影响：0.13 mM β-甲基-D-葡萄糖苷、0.28 mM D-葡萄糖、0.65 mM α-甲基-D-葡萄糖苷、0.77 mM 6-脱氧-D-葡萄糖、4.8 mM D-半乳糖和29 mM 3-O-甲基葡萄糖。当[Na]降低时，达到半数最大SCC增加所需的D-葡萄糖浓度升高。使用同位素标记的³H和¹⁴C D-葡萄糖同时测定双向通量；存在从顶端到基底外侧的净转运，且根皮苷可消除这种转运。转运的同位素与标记的D-葡萄糖共色谱，表明转运的葡萄糖代谢可忽略不计。猪肾细胞系LLC-PK1为研究跨上皮葡萄糖转运机制提供了一个细胞培养模型。
