USE OF HUMAN PSEUDO-EPIDERMIS TO EVALUATE THE TOXICITY OF BIS-(2-CHLOROETHYL)SULFIDE (BCES) ON WATER PERMEATION BARRIER FORMATION AND FUNCTION

Human pseudo-epidermis was used to investigate the effects of bis-(2-c hloroethyl)sulfide (BCES) on the formation and function of the water p ermeation barrier. To generate the culture, 2 million viable basal cel ls derived from human skin were plated on a Puropore nylon microporous membrane pre-coated with calf skin collagen. Addition of bovine pitui tary extract and epidermal growth factor to the medium favored the for mation of homogeneous cultures and better barrier function. The water permeation constant (K-rho) was shown to decrease significantly and re ached 25 +/- 6 x 10(-3) when it was calculated from 71% of the culture s prepared. The effects of topically applied BCES on the incorporation of [C-14]linoleic acid, as a marker for lipid synthesis, and K-rho, a s a measure of water permeation, were studied. Compared with untreated cultures, there was no difference in the K-rho immediately after expo sure to 1-10 nmol BCES/cm(2) for 30 min. On the other hand, [C-14]lino leic acid incorporation was dose-dependently decreased immediately aft er exposure and then returned to normal by 48 h later. These data sugg est that BCES produces no direct damage to the water permeation barrie r but may affect barrier formation by inhibiting lipid synthesis.