Electrical determination of water content and concentration profile in a simulation model of in vivo stratum corneum.
Electrical determination of water content and concentration profile in a simulation model of in vivo stratum corneum.
复制标题
体内角质层模拟模型中水含量和浓度分布的电测定。
DOI：
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发表时间：
1989
影响因子：
6.5
通讯作者：
Hachiro Tagami
中科院分区：
文献类型：
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作者：
M. Obata;Hachiro Tagami
由于其高效的保水能力，健康的角质层 (SC) 在任何环境条件下都可以保持柔软和富有弹性。然而，在面对潮湿的下面的活体组织的最下层和暴露于相对干燥的环境大气的SC的表面部分之间，SC内的水含量可能存在很大差异。为了更好地了解 SC 的水分布，并验证用于评估皮肤表面水合状态的高频电导测量的准确性，我们设计了一种简单方便的 SC 体外模型，可以刺激 SC 的体内设置。它由一张隔离的 SC 片组成，其下表面覆盖一块水饱和的滤纸垫，其上表面暴露于周围大气。通过将该模型放置在不同相对湿度 (RH) 的环境中，我们确认记录的电导值与 SC 的实际含水量具有良好的相关性 (r = 0.94)。使用具有五层 SC 片材的模型，SC 最内层部分的含水量估计相当于其干重的约 90%；这种水含量水平在很宽的环境相对湿度范围内保持相对恒定，除了在相对湿度高于 90% 的极端潮湿环境中，此时水开始在整个 SC 中过度积聚。使用这个五层 SC 片模型，清楚地表明从 SC 的最下层到最上层存在几乎直线的水浓度梯度。我们还证实，高频电流的皮肤电导与SC表层部分以及整个SC的含水量密切相关，因此，它是SC表层水合状态的良好参数。
Because of its efficient water-holding capacity, healthy stratum corneum (SC) can stay soft and flexible under any environmental conditions. There may be, however, a great difference in water content within the SC between the lowermost layer that faces the wet underlying living tissue and the superficial portion of the SC that is exposed to the relatively dry ambient atmosphere. To better understand the water profile of the SC and also to verify the accuracy of measurements of high frequency conductance used to evaluate the hydration state of the skin surface, we devised a simple and convenient in vitro model of the SC that stimulates the in vivo setting of the SC. It consists of an isolated sheet of SC whose lower surface covers a pad of water-saturated filter paper, and its upper surface is exposed to the ambient atmosphere. By placing this model in environments with different relative humidities (RH), we confirmed that the recorded conductance values correlated well with the actual water content of the SC (r = 0.94). Using a model having five layers of SC sheets, the water content of the innermost portion of the SC was estimated to be equivalent to about 90% of its dry weight; this level of water content remaining relatively constant over a wide range of ambient RH except in extraordinarily humid environments above 90% RH when water began to accumulate excessively in the whole SC. Using this five SC-sheet model, it was clearly demonstrated that there was an almost straight water concentration gradient from the lowermost layer to the uppermost layer of the SC. We also confirmed that the skin conductance of the high frequency current correlated well with the water content of the superficial portion of the SC as well as with that of the whole SC, therefore, it is a good parameter of the hydration state of the superficial layer of the SC.