The Water Barrier in Human Epidermis

摘要: The rate of water vapor transpiration through normal excised human skin at 10 to 20 C is 2.9 gm/sq m/hr, with a standard deviation 1.9 m/hr. not affected by freezedrying, rapid freezing in 15% glycerol solution 68 C, exposure 0.1 sodium hydroxide or 6 M urea for 24 hours, boiling flaming benzene so long as the stratum corneum visibly physically disrupted. Stratum corneum, an intact barrier, can be separated from cellular epidermis digestion hours 3% trypsin 37 C. has no identifiable basal layers. Extraction ether 8 increases cutaneous fourfold ninefold. acetone 3 followed extraction hexane removes its barrier properties and 75-fold. Replacing substances removed acetone-hexane onto surface extracted, water-vapor-barrier-lacking almost completely restores normal, indicating that physical structural characteristics have little do maintenance barrier. A theoretical scheme physical-chemical nature based on our observations, previous data, presented. This complex about 98% efficient. Water moved having 2.9±1.9 gm/ sq m/hr temperatures varying between while it barrierdeficient 229±81 same temperatures.