Reactivity of epidermal Langerhans cells to a histochemical method for demonstration of beta-glucuronidase

Sheets or sections of mouse epidermis reacted by a histochemical method for the enzyme beta-glucuronidase display a subpopulation of dendritic cells which correspond in number and spacing to Langerhans cells demonstrated by reactivity for ATPase or Ia antigens. A similar staining pattern is seen in rat, rabbit, and guinea pig epidermis. In rhesus monkey and human skin, Langerhans cells appear to be reactive for beta-glucuronidase but, as keratinocytes are also reactive, Langerhans cells are not readily identifiable by this method. The thermal stability of beta-glucuronidase differs between strains of mice. Langerhans cells of Balb/C and C3H strains can thus be distinguished by appropriate pretreatment before incubation, a method of potential value for experimental investigations of the origin of Langerhans cells.