Histochemical and immunological demonstration of purple acid phosphatase in human and bovine alveolar macrophages.

A tartrate-resistant purple acid phosphatase was localized in human and bovine alveolar macrophages by enzyme- and immuno-histochemistry using an antibody to bovine spleen purple phosphatase. The enzyme could be detected in human and bovine lung tissues as well as on cytospin preparations of alveolar macrophage suspensions from bronchoalveolar lavages. The immunological identity of human and bovine purple phosphatases from alveolar macrophages was demonstrated by Western blot analysis of material separated by polyacrylamide gel electrophoresis. A possible significance of the purple phosphatase as a marker enzyme of activated cells of the mononuclear phagocyte system is discussed.