Transport of tetraethylammonium by a kidney epithelial cell line (LLC-PK1).
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.
Fauth
C
C
Institut de Pharmacologie de l'Université de Lausanne, Switzerland.
Rossier
B
B
Roch-Ramel
F
F
D000818:Animals; D001692:Biological Transport; D002412:Cations / Q000494:pharmacology; D002460:Cell Line; D003470:Culture Media; D003584:Cytological Techniques; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D007668:Kidney / Q000166:cytology / Q000378:metabolism*; D009994:Osmolar Concentration; D010042:Ouabain / Q000494:pharmacology; D013696:Temperature; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000037:antagonists & inhibitors / Q000493:pharmacokinetics*; D013997:Time Factors
D002412:Cations; D003470:Culture Media; D013757:Tetraethylammonium Compounds; D010042:Ouabain; D019789:Tetraethylammonium