Epidermal change can alter mechanical properties of hairless mouse skin topically treated with 1 alpha, 25-dihydroxyvitamin D-3

Wrinkle formation caused by photoaging clearly involves changes of extracel lular matrix components and mechanical properties of the skin. Recently, it was reported that the topical application of 1 alpha, 25-dihydroxyvitamin D-3 to hairless mouse skin induced wrinkling. Here we have evaluated the ef fect of topical application of 1 alpha, 25-dihydroxyvitamin D-3, which caus es skin wrinkling, on the mechanical properties of the hairless mouse (HR/I CR) skin, using a commercially available non-invasive in vivo instrument. T he elasticity element of the skin was unchanged, but the viscosity element significantly increased. Histologically, the epidermis became remarkably th ick, but no conspicuous changes were observed in the dermis. Changes in the mechanical properties of the skin after 1 alpha, 25-dihydroxyvitamin D-3 t reatment take place through epidermal physical variation, especially change s of viscosity elements. it is suggested that the visco-elastic properties of the epidermis are also attributable to the morphology as well as the mec hanical properties of the skin. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.