title: A possible regulation mechanism of water content in human stratum corneum via intercellular lipid matrix.
abstract: We studied the water regulation mechanism in human stratum corneum which is composed of corneocytes and intercellular lipid matrix by the ex vivo small- and medium-angle X-ray diffraction. Under the normal condition water molecules are stored mainly in the corneocytes. When the water content increased, from the small-angle X-ray diffraction of the human stratum corneum we obtained the swelling behavior of the short lamellar lipid structure as a result of incorporating a very small amount of water into water layers between neighboring the lipid bilayers, and its diffraction peak width became narrow and turned to wide at the water content of 20-30wt%. In addition as evidence for uptake of water in the corneocytes, we observed the structural modification of soft keratins in the corneocytes from the medium-angle X-ray diffraction. Based upon these results we propose that the water content in the human stratum corneum is regulated to be at 20-30wt% so as to stabilize the short lamellar structure in the intercellular lipid matrix.
authors.affiliation: Department of Physics, Kwansei Gakuin University, Gakuen, Sanda, Hyogo, Japan.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Nakazawa
authors.forename: Noboru
authors.initials: N
authors.lastname: Ohta
authors.forename: Ichiro
authors.initials: I
authors.lastname: Hatta
mesh_terms: D000328:Adult; D004817:Epidermis / Q000737:chemistry*; D005260:Female; D006801:Humans; D007633:Keratins / Q000737:chemistry; D008055:Lipids / Q000737:chemistry*; D014867:Water / Q000032:analysis*; D014961:X-Ray Diffraction
chemical_list: D008055:Lipids; D014867:Water; D007633:Keratins