Aldosterone does not stimulate the Na

K pump in isolated turtle colon

D. R. Halm, D. C. Dawson

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The study of the mechanisms by which mineralocorticoids stimulate sodium absorption across distal epithelia has focused on three possible sites of action: apical sodium permeability, the basolateral Na:K pump, and the production of high-energy substrates. Recently we developed a method for direct measurement of the current generated by the basolateral Na:K pump of the turtle colon [15]. In the presence of mucosal amphotericin-B and serosal barium the short-circuit current across the colon can be equated with the current produced by active electrogenic exchange of sodium for potassium across the basolateral membrane. This pump current is a measure of the transport capacity of the epithelial Na:K pump that is uncomplicated by changes in apical membrane sodium permeability. Pump currents, thus defined, were compared in control tissues and tissues treated with aldosterone in vitro. After 9 h Na absorption was increased 4-fold in the aldosterone-treated tissues but the values of the pump current were identical in the two groups. This result indicates that acute stimulation of sodium absorption by aldosterone does not occur by stimulating the Na:K pump directly.

Original languageEnglish (US)
Pages (from-to)236-239
Number of pages4
JournalPflugers Archiv European Journal of Physiology
Volume403
Issue number3
StatePublished - 1985
Externally publishedYes

Fingerprint

Turtles
Aldosterone
Colon
Sodium
Pumps
Permeability
Tissue
Mineralocorticoids
Membranes
Amphotericin B
Barium
Potassium
Epithelium
Short circuit currents
Substrates

ASJC Scopus subject areas

  • Physiology

Cite this

Aldosterone does not stimulate the Na : K pump in isolated turtle colon. / Halm, D. R.; Dawson, D. C.

In: Pflugers Archiv European Journal of Physiology, Vol. 403, No. 3, 1985, p. 236-239.

Research output: Contribution to journalArticle

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