ELECTROCHEMICAL DETERMINATION OF OXYGEN PERMEABILITY OF ISOLATED STRATUM-CORNEUM MEMBRANES

The mammalian stratum corneum is a thin, highly organized polymeric me mbrane which is relatively impermeable to water but permeable to some gases including oxygen. Isolated stratum corneum membranes from perina tal Sprague-Dawley rats were mounted under electrodes used to determin e the rate of diffusion of oxygen through the membrane. These membrane s were consistently found to be permeable to oxygen, which could be qu antitatively determined at a gold electrode at -0.6 V (vs. a Ag/AgCl e lectrode). The stratum corneum membrane was found to be anisotropic, w ith greater oxygen permeability when the gas diffused toward the elect rolyte from the side of the membrane which would be oriented toward th e exterior of the animal than when it diffused in the opposite directi on. There is also evidence of anatomic site heterogeneity in the perme ability of the membranes.