Fauth C, Rossier B, Roch-Ramel F
Institut de Pharmacologie de l'Université de Lausanne, Switzerland.
Am J Physiol. 1988 Mar;254(3 Pt 2):F351-7. doi: 10.1152/ajprenal.1988.254.3.F351.
We investigated whether the LLC-PK1 epithelial cell line (which shows many characteristics of proximal tubular cells) also is capable of transporting an organic ion. Suspended LLC-PK1 cells accumulated tetraethylammonium (TEA). The uptake showed characteristics of a facilitated mechanism; TEA uptake was saturable and temperature-dependent and was inhibited by other organic cations. Quinine and mepiperphenidol were the most potent inhibitors, whereas N1-methylnicotinamide and morphine inhibited the transport system only slightly at doses of 10(-3) M. Basolateral-to-apical TEA flux through LLC-PK1 monolayers was five to six times larger than that of mannitol, a nontransported compound, whereas apical-to-basolateral TEA and mannitol fluxes were equal. Only the basolateral-to-apical TEA flux was inhibited by quinine. Under similar experimental conditions, no transport of p-aminohippuric acid was observed. It is concluded that LLC-PK1 cells are able to transport TEA, as do cells of the proximal tubule.
我们研究了LLC - PK1上皮细胞系（其表现出许多近端肾小管细胞的特征）是否也能够转运有机离子。悬浮的LLC - PK1细胞积累四乙铵（TEA）。摄取表现出易化机制的特征；TEA摄取是可饱和的且依赖温度，并受到其他有机阳离子的抑制。奎宁和美哌隆是最有效的抑制剂，而N1 - 甲基烟酰胺和吗啡在10⁻³ M剂量时仅轻微抑制转运系统。通过LLC - PK1单层细胞从基底外侧到顶端的TEA通量比非转运化合物甘露醇大五到六倍，而从顶端到基底外侧的TEA和甘露醇通量相等。只有从基底外侧到顶端的TEA通量受到奎宁的抑制。在类似的实验条件下，未观察到对氨基马尿酸的转运。结论是LLC - PK1细胞能够像近端肾小管细胞一样转运TEA。
