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

Citation
M. Fronius et al., Inhibitory non-genomic effects of progesterone on Na+ absorption in epithelial cells from Xenopus kidney (A6), J COMP PH B, 171(5), 2001, pp. 377-386
Citations number
44
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Animal Sciences",Physiology
Journal title
JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMIC AND ENVIRONMENTALPHYSIOLOGY
ISSN journal
0174-1578 → ACNP
Volume
171
Issue
5
Year of publication
2001
Pages
377 - 386
Database
ISI
SICI code
0174-1578(200106)171:5<377:INEOPO>2.0.ZU;2-M
Abstract
The effect of the steroid hormone progesterone on transepithelial sodium tr ansport was measured in confluent monolayers of the A6-cell line from Xenop us kidney. Apical permeabilization with Amphotericin B enabled us to measur e the Na+/K+-pump current, and current-fluctuation analysis was used to ana lyze changes in apical channel density and gating characteristics. Basolate ral progesterone (22.2 muM) had a rapid inhibitory effect on the Na+/K+-pum p 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 st ate, in which 45% of the macroscopic current (I-SC) was inhibited. Progeste rone also inhibits the hypo-osmotic stimulation of Na' channels which occur s in untreated monolayers. Compared with the known effects of adrenal stero ids, 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.