USE OF CONTINUOUS ELECTRICAL CAPACITANCE AND TRANSEPIDERMAL WATER-LOSS MEASUREMENTS FOR ASSESSING BARRIER FUNCTION IN NEONATAL RAT SKIN

A vital function of the skin is to oppose the loss of water to the env ironment. In this study, two complementary methods, transepidermal wat er loss (TEWL) and continuous electrical capacitance under occlusion, were used to assess epidermal barrier function in a developmental anim al model, the neonatal Sprague-Dawley rat. TEWL monitors barrier funct ion directly while the increase in capacitance under occlusion is rela ted to both the skin's barrier function and to its water holding capac ity. Serial tape stripping of the stratum corneum on 1-day-old rat pup s led to a significant increase in both TEWL and continuous capacitanc e measurements. Anatomic site heterogeneity and the effects of surface temperature were also studied. The ventral skin surface exhibited an increase in the continuous capacitance measurements, an effect possibl y due to the thinner stratum corneum on the ventral side. Both TEWL an d continuous capacitance values were directly correlated with ambient temperatures within the physiological range.