Physiological and functional changes in the stratum corneum restored by oestrogen in an ovariectomized mice model of climacterium.

ABSTRACT

Significant decreases in hormonal levels at menopause induce physiological and functional discomfort in the skin. Representative changes at menopause are based on so-called dry skin. However, there is no evidence to explain the mechanism, even though hydration of the stratum corneum (SC) in women at menopause is comparable with that at premenopause but is enhanced by hormone replacement therapy. This study objective was to evaluate structural and functional changes in the SC in ovariectomized mice model of menopause. Hydration of the SC, recovery of the permeability barrier function, integrity and cohesion of the SC, and irritant dermatitis were analysed in mice that underwent ovariectomy with or without replacement of 17ß-estradiol. In ovariectomized mice, hydration of the SC was reduced, recovery of permeability barrier function after acute disruption was impaired, and integrity of the SC was weakened and was associated with increased cohesion and increased levels of irritant dermatitis. Oestrogen replacement treatment restored all changes. Immunohistochemistry revealed reduced levels of expression of desmoglein-1 and differentiation markers of epidermis in ovariectomized mice compared with control mice and mice with oestrogen replacement treatment. These changes might be directly associated with weakened integrity and impaired permeability barrier function of the SC in ovariectomized mice. This study results reveal that so-called dry skin at menopause is caused by not only lower hydration of the SC but also complicated structural and functional changes in the SC and skin.