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Influx and Efflux of Sodium at the Outer Surface of Frog Skin

Overview
Journal J Membr Biol
Date 1975 Jan 1
PMID 1079878
Citations 17
Authors
R Rick
A Dorge
W Nagel
Affiliations
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Abstract

The unidirectional Na influx j12, and Na efflux, j12, at the epithelial surface of the frog skin were determined under various experimental conditions. The j21 was taken as the difference between j12 and the simultaneously measured shortcircuit current (SCC). Errors in j12 determination originating from various transport rates within the skin were kept to a minimum using a normalization procedure. Under control conditions, j12 (1.20 muEquiv/cm-2. hr) was found to be only slightly larger than the SCC (1.10 MUEquiv/cm-2. hr). After inhibition of the transepithelial Na transport by amiloride, ouabain, low temperature and low Na concentration, the reduction of j12 and SCC was almost identical, indicating that the entrance of Na into the epithelium is rate limiting for the transepithelial transport. Compared to the control, j21 remained unchanged after amiloride and ouabain, but was insignificantly reduced at low temperature and significantly reduced at low Na concentration. These data are consistent with the assumption that the Na efflux follows mainly an extracellular pathway.

Citing Articles

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References
1.
Cereijido M, Rotunno C . The effect of antidiuretic hormone on Na movement across frog skin. J Physiol. 1971; 213(1):119-33. PMC: 1331727. DOI: 10.1113/jphysiol.1971.sp009372. View
2.
Emilio M, Machado M, MENANO H . The production of a hydrogen ion gradient across the isolated frog skin. Quantitative aspects and the effect of acetazolamide. Biochim Biophys Acta. 1970; 203(3):394-409. DOI: 10.1016/0005-2736(70)90180-x. View
3.
Dorge A, Nagel W . Effect of amiloride on sodium transport in frog skin. II. Sodium transport pool and unidirectional fluxes. Pflugers Arch. 1970; 321(2):91-101. DOI: 10.1007/BF00586365. View
4.
Curran P, Herrera F, FLANIGAN W . The effect of Ca and antidiuretic hormone on Na transport across frog skin. II. Sites and mechanisms of action. J Gen Physiol. 1963; 46:1011-27. PMC: 2195298. DOI: 10.1085/jgp.46.5.1011. View
5.
USSING H, ZERAHN K . Active transport of sodium as the source of electric current in the short-circuited isolated frog skin. Acta Physiol Scand. 1951; 23(2-3):110-27. DOI: 10.1111/j.1748-1716.1951.tb00800.x. View