Pflügers Archiv

, Volume 412, Issue 4, pp 434–441

Ionic conductances of cultured principal cell epithelium of renal collecting duct

Authors

  • Peter Gross
    • Sektion NephrologieMedizinische Universitätsklinik
  • Will W. Minuth
    • I. Anatomisches Institut der Universität Heidelberg
  • Markus Ketteler
    • Sektion NephrologieMedizinische Universitätsklinik
  • Eberhard Frömter
    • Zentrum der Physiologie
  • Rita Böhm
    • Sektion NephrologieMedizinische Universitätsklinik
Transport Processes, Metabolism and Endocrinology; Kidney, Gastrointestinal Tract, and Exocrine Glands

DOI: 10.1007/BF01907564

Cite this article as:
Gross, P., Minuth, W.W., Ketteler, M. et al. Pflugers Arch. (1988) 412: 434. doi:10.1007/BF01907564

Abstract

The ionic conductive properties were studied of epithelia of collecting duct principal cells which had been grown in primary tissue culture from renal cortex/capsule explants. When pretreated with aldosterone (10−6 mol/l) and bathed on either surface with isotonic HCO3-free Ringer's solution, the transepithelial voltage,Vte, varied between −21 and −72 mV (apical surface negative) while the transepithelial resistance,Rte, ranged from 0.4 to 1.5 kΩcm2. By 10:1 step-changes in Na+ concentration the apical cell membrane was shown to have a high conductivity for sodium, inhibitable by amiloride, 10−6 mol/l. However, contrary to observations in natural collecting duct under control conditions, amiloride never reversed the polarity ofVte even at 10−4 mol/l. Both the apical and the basolateral cell membranes were conductive for potassium and both conductivities were inhibitable by Ba2+ (5 mmol/l). 10:1 reduction of apical Cl concentration strongly hyperpolarizedVte with a monophasic time course suggesting the presence of a paracellular shunt conductance for Cl. In addition there may be a small Cl conductance present in the apical cell membrane since apical application of the chloride channel blocker 5-nitro-2-(3-phenylpropylamino)-benzoic acid (NPPAB) at 10−7 mol/l produced a minute but significant hyperpolarization. On the other hand, 10:1 reduction of basolateral Cl concentration caused a biphasic change inVte (initial depolarization, followed by repolarization) which indicates the presence of a large Cl conductance in the basolateral cell membrane. The latter was not inhibitable by 10−7 mol/l NPPAB. Higher concentrations of this and of an other Cl channel blocker produced non-specific effects. In conclusion, our studies of a pure principal cell epithelium confirm findings described for the intact cortical collecting duct and add new information concerning chloride conductivity and related blocking agents.

Key words

Collecting ductPrincipal cellTissue cultureChloride conductivity
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© Springer-Verlag 1988