The Journal of Membrane Biology

, Volume 42, Issue 2, pp 169–187

Amiloride and calcium effect on the outer barrier of the frog skin

  • C. A. Rabito
  • C. A. Rotunno
  • M. Cereijido
Article

DOI: 10.1007/BF01885369

Cite this article as:
Rabito, C.A., Rotunno, C.A. & Cereijido, M. J. Membrain Biol. (1978) 42: 169. doi:10.1007/BF01885369
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Summary

Amiloride (0.1mm) as well as Ca++ (10mm) inhibit Na+ transport across frog skin by blocking Na+ entrance across the outer barrier of the epithelium. The inhibition produced by amiloride consists of an “early” and a “late” phase which together account for almost a total inhibition of the short-circuit current (SCC). The analysis of the time course indicates that the two phases are due to the inhibition of superficially and deeply located Na sites, respectively. Ca++, instead, only blocks a fraction of the SCC, and this fraction seems to correspond to the inhibition of the same population of Na sites blocked by the “late” phase of amiloride effect. The location of the two populations of Na sites as well as the possible relationship between them are discussed in terms of maturation of the outermost cell layer.

Copyright information

© Springer-Verlag New York Inc. 1978

Authors and Affiliations

  • C. A. Rabito
    • 1
    • 2
  • C. A. Rotunno
    • 1
    • 2
  • M. Cereijido
    • 1
    • 2
  1. 1.Department of BiophysicsAlbert Einstein Center of Medical Research (CIMAE) of Buenos AiresArgentina
  2. 2.Centro de Investigaciones y Estudios Avanzados del I.P.N. of MéxicoMéxicoMexico
  3. 3.Dept. of PathologyMedical College of PennsylvaniaPhiladelphia