Said Lilian, Serup Jørgen, Rebel Carl
Department of Dermatology and Department of Clinical Chemistry, Linköping University Hospital, Sweden.
Skin Res Technol. 2002 Nov;8(4):219-26. doi: 10.1034/j.1600-0846.2002.00347.x.
BACKGROUND/AIMS: Epidermis forms the protective barrier of the skin by its outermost layer, stratum corneum. The purpose of this study was to investigate the epidermal barrier in view of epidermal calcium release (ECR), phosphate release, transepidermal water loss (TEWL) and skin surface pH. Calcium is mainly an intracellular ion. Calcium was sampled introducing a new and simple washout chamber technique for the study of epidermal release in vivo.
Test sites on forearms of 13 healthy subjects were pre-treated with 24 h water occlusion, 24 h 2% sodium lauryl sulphate (SLS) or tape stripped. Both untreated and pre-treated test sites were exposed to a water washout chamber with 200 micro deionized water as a solvent. Water washout chambers were removed after two hours and calcium and phosphate in the water was analyzed. Transepidermal water loss and pH were measured before and after the trial.
pH increased after tape stripping and after exposure to SLS. Transepidermal water loss increased significantly at all test sites. Calcium was significantly released from SLS-treated sites but not from tape stripped sites. There was generally a correlation between ECR, phosphate release, TEWL and pH. In this study ECR is showed to be a barrier marker of high reproducibility.
Epidermal calcium release or ECR is found useful as an indicator of skin barrier function. Calcium release and increase of pH appear mainly to illustrate direct and corrosive damage to epidermal cells and functions contrasting TEWL, in this experiment probably reflecting intercellular damage of fracturing as exemplified by mechanical damage resulting from surface stripping. This new distinction of skin barrier damage into cellular damage resulting from a corrosive chemical trauma and intercellular damage and fracturing resulting from a mechanical trauma is exemplified in SLS provocative testing and tape stripping, the former characterized by increased ECR. The washout chamber technique was deemed technically reliable and reproducible, and has a major potential in experimental dermatology and skin pharmacology for the study of in vivo epidermal release of a range of endogenous and exogenous substances.
背景/目的：表皮通过其最外层角质层形成皮肤的保护屏障。本研究旨在从表皮钙释放（ECR）、磷酸盐释放、经表皮水分流失（TEWL）和皮肤表面pH值方面研究表皮屏障。钙主要是一种细胞内离子。采用一种新的简单冲洗室技术对体内表皮释放进行研究来采集钙样本。
对13名健康受试者的前臂测试部位进行预处理，分别采用24小时水封闭、24小时2%十二烷基硫酸钠（SLS）处理或胶带剥离。未处理和预处理后的测试部位均暴露于装有200微升去离子水作为溶剂的水冲洗室中。两小时后移除水冲洗室，并分析水中的钙和磷酸盐。在试验前后测量经表皮水分流失和pH值。
胶带剥离后以及暴露于SLS后pH值升高。所有测试部位的经表皮水分流失均显著增加。钙从SLS处理的部位显著释放，但胶带剥离部位未出现这种情况。ECR、磷酸盐释放、TEWL和pH值之间通常存在相关性。在本研究中，ECR被证明是一种具有高重现性的屏障标志物。
发现表皮钙释放或ECR可作为皮肤屏障功能的指标。钙释放和pH值升高似乎主要说明了对表皮细胞和功能的直接腐蚀性损伤，与TEWL形成对比，在本实验中可能反映了如表面剥离导致的机械损伤所例证的细胞间破裂损伤。皮肤屏障损伤的这种新分类，即腐蚀性化学创伤导致的细胞损伤以及机械创伤导致的细胞间损伤和破裂，在SLS激发试验和胶带剥离中得到例证，前者的特征是ECR增加。冲洗室技术在技术上被认为是可靠且可重现的，在实验皮肤病学和皮肤药理学中对于研究一系列内源性和外源性物质的体内表皮释放具有重大潜力。
