Polarized distribution of oxalate transport systems in LLC-PK1 cells, a line of renal epithelial cells

Am J Physiol. 1994 Feb;266(2 Pt 2):F266-74. doi: 10.1152/ajprenal.1994.266.2.F266.

Abstract

Although oxalate is a major component of kidney stones, the factors affecting renal oxalate handling are poorly understood. This uncertainty stems in part from complexities inherent to available preparations; thus the present studies examined oxalate handling in a simpler model system, LLC-PK1 cells, an epithelial cell line of porcine origin. Initial studies on monolayers in dishes demonstrated that these cells accumulate oxalate via a process or processes sensitive to the anion transport inhibitor 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). Subsequent studies using LLC-PK1 monolayers on membrane filters examined the characteristics and distribution of these transporter(s). At the apical surface, DIDS-sensitive uptake was sensitive to [Cl-] but not [SO4(2-)] or [HCO3-] and was unaffected by alterations in pH or membrane potential. At the basolateral surface, oxalate uptake was [Cl-] insensitive but markedly affected by variation in pH, [SO4(2-)], or [HCO3-]. Uptake at the two membrane surfaces was also differentially affected by transport inhibitors and organic acids. Thus LLC-PK1 cells appear to express unique transporters at each membrane surface: oxalate/Cl- exchange at the apical surface and oxalate/SO4(2-) (or HCO3-) exchange at the basolateral surface.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / pharmacology
  • Animals
  • Anions / pharmacology
  • Biological Transport / drug effects
  • Carboxylic Acids / pharmacology
  • Cell Line
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism
  • Chlorides / pharmacology
  • Epithelium / drug effects
  • Epithelium / metabolism
  • Furosemide / pharmacology
  • Hydrogen-Ion Concentration
  • Kidney / metabolism*
  • Kinetics
  • Oxalates / metabolism*
  • Probenecid / pharmacology
  • Time Factors

Substances

  • Anions
  • Carboxylic Acids
  • Chlorides
  • Oxalates
  • Furosemide
  • Probenecid
  • 4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid