8 JOURNAL OF COSMETIC SCIENCE deficient mice display normal barrier repair kinetics, indicating that signalling pathways independent from IL 1-alpha predominate the barrier repair response, including stimu- lation of lipid synthesis (30). Taurine inhibits the activity of potassium ion channels (31). It has been shown that potassium ions inhibit permeability barrier repair (32). Therefore, taurine might regu- late barrier function by altering the intraepidermal transport of potassium ions. It has been shown that glycerol accelerates barrier recovery after acute disruption (33). However, the effect of taurine appears to be much more prominent because in this study a significant effect was observed at 1 % taurine in the presence of 2.5% glycerol. In contrast, the vehicle containing 2.5% glycerol alone had no significant effect on SDS- induced barrier perturbation. UV irradiation also triggers skin inflammation, barrier lipid synthesis, and taurine accumulation (7 ,34}. Therefore, future studies will focus on the effects of taurine on UV-induced skin irritation. CONCLUSION Our data suggest a role for taurine in preventing surfactant-induced dry and scaly skin by modulating the proinflammato ry response and stimulating epidermal lipid synthesis. Because barrier repair is diminished in aged epidermis (3 5 ), taurine might be especially useful to prevent surfactant-induced dry and scaly skin in the elderly. ACKNOWLEDGMENTS We thank Mrs. Christiane Bossmann-Tesch and Dr. Daniela Kessler-Becker from Hen- kel KGaA (Duesseldorf, Germany) for their excellent support with skin lipid analysis and in vitro skin irritation. We also thank Dr. Vera Meienschein, Dr. Thomas Gassen- meier, Dr. Ruediger Graf, and Dr. Michael Kock from Phenion GmbH & Co KG (Frankfurt, Germany) for their helpful discussions. REFERENCES (1) R.R. Warner, M. C. Myers, and D. A. Taylor, Electron probe analysis of human skin: Determination of the water concentration profile,]. Invest. Dermatol., 90, 218-224 (1988). (2) P. J. Caspers, G. W. Lucassen, E. A. Carter, H. A. Bruining, and G. J. Puppels, In vivo confocal Raman microspectroscopy of the skin: Noninvasive determination of molecular concentration profiles,]. Invest. Dermatol., 116, 434-442 (2001). (3) M. B. Burg, Molecular basis of osmotic regulation, Am. J. Physiol., 268, 983-996 (1995). (4) F. X. Beck, A. Burger-Kentischer, and E. Muller, Cellular response to osmotic stress in the renal medulla, Pflugers Arch., 436, 814-827 (1998). (5) M. V. Lobo, F. J. Alonso, A. Latorre, and R. Martin del Rio, Taurine levels and localisation in the stratified squamous epithelia, Histochem. Cell Biol., 115, 341-347 (2001). (6) G. Janeke, W. Siefken, S. Carstensen, G. Springmann, 0. Bleck, H. Steinhart, P. Hoger, K. P. Wittern, H. Wenck, F. Stab, G. Sauermann, V. Schreiner, and T. Doering, Role of taurine accumu- lation in keratinocyte hydration,]. Invest. Dermatol., 121, 354-361 (2003). (7) U. Warskulat, A. Reinen, S. Grether-Beck, J. Krutmann, and D. Haussinger, The osmolyte strategy

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