CALCIUM AND POTASSIUM INHIBIT BARRIER RECOVERY AFTER DISRUPTION, INDEPENDENT OF THE TYPE OF INSULT IN HAIRLESS MICE

Disruption of the cutaneous permeability barrier induces metabolic res ponses in the epidermis which result in barrier recovery. Barrier disr uption by either solvent treatment or tape stripping results in the lo ss of the epidermal calcium gradient. Previous studies in acetone trea ted hairless mice have shown that maintaining this calcium gradient in hibits barrier repair. suggesting that alterations in the epidermal ca lcium concentration may be an important signal for barrier homeostasis . In the present study, we show that in hairless mice disruption of th e barrier by treatment with the detergent, SDS, also results in the lo ss of the calcium gradient. as demonstrated both semi-quantitatively w ith ultrastructural cytochemical localization and quantitatively using proton induced X-ray emission (PIXE). Additionally, immersion in calc ium containing solutions delays barrier repair after either detergent (SDS treatment) or mechanical (tape stripping) disruption of the barri er, as reported previously for acetone treated skin. These results ind icate that barrier disruption, regardless of the insult, induces chang es in the epidermal calcium gradient which may play an important role in signaling the metabolic changes required for barrier homeostasis.