Location and nature of the epidermal permeability barrier.
Synopsis The lowest region of human and pig stratum corneum has been isolated as an integral layer, referred to as the stratum compactum. This preparation is resistant to disruption by enzymes, 6M urea, Triton X-100 and organic solvents. Our evidence suggests that penetration of materials to and through the corneum depend on the state of cohesion between cells, and of the organization of intercellular lipid species. As the cells move up towards the outside of the stratum corneum, the cohesive forces are reduced due to desmosome degradation and lipid modifications, with ultimate dyshesion and sloughing of individual cells. A number of linoleate-rich lipids have been identified within human and pig epidermis which could contribute to the formation or maintenance of an epidermal permeability barrier. Our current belief is that the molecule key to barrier function is a hydroxylated linoleate derivative which appears to be formed in the stratum compactum region.
Bowser
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PA
Unilever Research, Port Sunlight, Wirral, Merseyside L63 3JW.
White
R J
RJ
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