[ATPase positive epidermal Langerhans cells: inhibition of ATPase by ammonium bituminosulfonate (Ichthyol) and pix lithanthracis].

Both, ammonium bituminosulfonate (Ichthyol) and Pix lithanthracis reduce the number of ATPase-positive epidermal Langerhans cells (ELC) in the epidermis of BALB/c mice: vaselinum flavum alone vs vaselinum flavum +5% Ichthyol: P less than 0.01; vaselinum flavum vs vaselinum flavum +5% Pix lithanthracis: P less than 0.001. In contrast to this, the number of Ia-positive cells was not changed under identical conditions. These results allow the conclusion that Ichthyol and Pix lianthracis are able to inhibit the enzyme ATPase on the surface of ELC. We infer that inhibition of ELC ATPase may be important in the regulation of ELC function (inhibition of cutaneous contact hypersensitivity).