Faculty Publications

Amiloride Stimulation of Sodium Transport in the Presence of Calcium and Divalent Cation Chelator

Document Type

Article

Keywords

(Toad bladder), Amiloride stimulation, Ca dependence 2+, Divalent cation chelator, EDTA, Epithelial transport, Na transport +, Short circuit current

Journal/Book/Conference Title

BBA - Biomembranes

Volume

689

Issue

3

First Page

561

Last Page

566

Abstract

Amiloride in nM to μM concentrations stimulates the short circuit current (Isc) of the toad urinary bladder by as much as 120% when applied in conjunction with apical Ca2+ and a divalent cation chelator. A significant decrease in transepithelial resistance (Rt) is observed simultaneously. This response is spontaneously reversible and its amplitude is dependent upon apical sodium concentrations. The stimulated Isc persisted when acetazolamide (1 mM) was introduced, HPO42- substituted for HCO3- or SO42- replaced Cl-. Consequently, the increase in Isc is not due to the change of Cl-, H+ or HCO3- flux. This behavior in a 'tight' epithelium may be related to the mechanism controlling apical sodium permeability. © 1982.

Department

Department of Biology

Original Publication Date

8-12-1982

DOI of published version

10.1016/0005-2736(82)90314-5

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