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Journal of Comparative Physiology B

, Volume 171, Issue 5, pp 377–386 | Cite as

Inhibitory non-genomic effects of progesterone on Na+ absorption in epithelial cells from Xenopus kidney (A6)

  •  M. Fronius
  •  M. Rehn
  •  U. Eckstein-Ludwig
  •  W. Clauss
Original Paper

Abstract.

The effect of the steroid hormone progesterone on transepithelial sodium transport was measured in confluent monolayers of the A6-cell line from Xenopus kidney. Apical permeabilization with Amphotericin B enabled us to measure the Na+/K+-pump current, and current-fluctuation analysis was used to analyze changes in apical channel density and gating characteristics. Basolateral progesterone (22.2 µM) had a rapid inhibitory effect on the Na+/K+-pump current, and a corresponding decrease in Na+ channel density. The effect occurred within some minutes and took about 50 min to reach a new steady state, in which 45% of the macroscopic current (Isc) was inhibited. Progesterone also inhibits the hypo-osmotic stimulation of Na+ channels which occurs in untreated monolayers. Compared with the known effects of adrenal steroids, our results show a rapid inhibitory action of a steroid hormone on Na+ absorption. The time profile of the progesterone effect suggests, at least in the first minutes, a non-genomic action of progesterone.

A6-cell line Noise analysis Na+/K+-pump ENaC Progesterone 

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Copyright information

© Springer-Verlag 2001

Authors and Affiliations

  •  M. Fronius
    • 1
  •  M. Rehn
    • 1
  •  U. Eckstein-Ludwig
    • 1
  •  W. Clauss
    • 1
  1. 1.Institute of Animal Physiology, Justus-Liebig-University Giessen, Wartweg 95, 35392 Giessen, Germany

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