title: Hypo-osmotic shock-induced subclinical inflammation of skin in a rat model of disrupted skin barrier function.
abstract: Aging disrupts skin barrier function and induces xerosis accompanied by pruritus. In many cases, elderly patients complain of pruritus during skin hygiene care, a condition called aquagenic pruritus of the elderly (APE). To date, the pathophysiology and mechanism of action of APE have not been elucidated. We conducted the present study to test the hypothesis that hypo-osmotic shock of epidermal cells induces skin inflammation and elongation of C-fibers by nerve growth factor β (NGFβ) as a basic mechanism of APE. The dorsal skin of HWY rats, which are a model for disrupted skin barrier function, was treated with distilled water (hypotonic treatment [Hypo] group) or normal saline (isotonic treatment [Iso] group) by applying soaked gauze for 7 days. Untreated rats were used as a control (no-treatment [NT] group). Histochemical and immunohistochemical analyses revealed inflammatory responses in the epidermis and the dermal papillary layer in the Hypo group, while no alterations were observed in the Iso or NT groups. Induction of expression and secretion of NGFβ and elongation of C-fibers into the epidermis were found in the Hypo group. In contrast, secretion of NGFβ was significantly lower and elongation of C-fibers was not observed in the Iso group. These results suggest that hypo-osmotic shock-induced inflammatory reactions promote hypersensitivity to pruritus in skin with disrupted barrier function.
authors: Department of Gerontological Nursing/Wound Care Management, Division of Health Sciences and Nursing, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Chihiro
authors: C
authors: Kishi
authors: Department of Gerontological Nursing/Wound Care Management, Division of Health Sciences and Nursing, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Takeo
authors: T
authors: Minematsu
authors: Department of Gerontological Nursing/Wound Care Management, Division of Health Sciences and Nursing, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Lijuan
authors: L
authors: Huang
authors: Department of Gerontological Nursing/Wound Care Management, Division of Health Sciences and Nursing, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Yuko
authors: Y
authors: Mugita
authors: Department of Gerontological Nursing/Wound Care Management, Division of Health Sciences and Nursing, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Aya
authors: A
authors: Kitamura
authors: Department of Gerontological Nursing/Wound Care Management, Division of Health Sciences and Nursing, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Gojiro
authors: G
authors: Nakagami
authors: Department of Gerontological Nursing/Wound Care Management, Division of Health Sciences and Nursing, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Takumi
authors: T
authors: Yamane
authors: Department of Life Support Technology (Molten), Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Mikako
authors: M
authors: Yoshida
authors: Department of Life Support Technology (Molten), Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Hiroshi
authors: H
authors: Noguchi
authors: Department of Gerontological Nursing/Wound Care Management, Division of Health Sciences and Nursing, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Megumi
authors: M
authors: Funakubo
authors: Department of Life Support Technology (Molten), Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors: Taketoshi
authors: T
authors: Mori
authors: Department of Gerontological Nursing/Wound Care Management, Division of Health Sciences and Nursing, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan hsanada-tky@umin.ac.jp.
authors: Hiromi
authors: H
authors: Sanada
mesh_terms: D000368:Aged; D000818:Animals; D006801:Humans; D007150:Immunohistochemistry; D007249:Inflammation; D008297:Male; D009997:Osmotic Pressure; D011537:Pruritus / Q000209:etiology; D051381:Rats; D012867:Skin / Q000473:pathology / Q000503:physiopathology*
keywords: elderly; hygiene care; hypo-osmotic shock; inflammation; skin barrier function