Abstract

The objective of this study was to determine whether a structurally heterogeneous biomembrane, human stratum corneum (SC), behaved as a homogeneous barrier to water transport. The question is relevant because the principal function of the SC in vivo is to provide a barrier to the insensible loss of tissue water across the skin. Impedance spectra (IS) of the skin and measurements of the rate of transepidermal water loss (TEWL) were recorded sequentially in vivo in human subjects as layers of the SC were progressively removed by the serial application of adhesive tape strips. The low-frequency (≤100 rad s-1) impedance of skin was much more significantly affected by tape stripping than the higher frequency values; removal of the outermost SC layer had the largest effect. In contrast, TEWL changed little as the outer SC layers were stripped off, but increased dramatically when 6- 8 μm of the tissue had been removed. It follows that the two noninvasive techniques probe SC barrier integrity in somewhat different ways. After SC removal, recovery of barrier function, as assessed by increasing values of the low-frequency impedance, apparently proceeded faster than TEWL decreased to the prestripping control. The variation of TEWL as a function of SC removal behaved in a manner entirely consistent with a homogeneous barrier, thereby permitting the apparent SC diffusivity of water to be found. Skin impedance (low frequency) was correlated with the relative concentration of water within the SC, thus providing an in vivo probe for skin hydration. Finally, the SC permeability coefficient to water, as a function of SC thickness, was calculated and correlated with the corresponding values of skin admittance derived from IS.

Original languageEnglish
Pages (from-to)2692-2700
Number of pages9
JournalBiophysical Journal
Volume71
Issue number5
DOIs
Publication statusPublished - 30 Nov 1996

Bibliographical note

Funding Information:
Financial support was provided by the U.S. National Institutes of Health (HD-23010 and HD-27839), the U.S. Air Force Office of Scientific Re- search, and the U.S. Environmental Protection Agency. FP is particularly grateful to Prof. P. Agache (Centre de Recherche sur le Tegument, France), Hoffmann-LaRoche, and the Philippe Foundation.

ASJC Scopus subject areas

  • Biophysics

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