Immunocytochemical localization of a tartrate-resistant and vanadate-sensitive acid nucleotide tri- and diphosphatase

Purified rabbit antiserum to a tartrate-resistant and vanadate-sensitive acid phosphatase (nucleotide tri- and diphosphatase) prepared from rat bone was used in immunocytochemical studies. The antigen was localized in sections of fixed, decalcified tissue (head from rat) using the peroxidase-antiperoxidase bridge (PAP) or the avidin-biotin-peroxidase complex (ABC) technique. Both techniques resulted in similar and specific immunostaining in the following cells and tissues: osteoclasts situated in resorption lacunae, epithelium overlying enamel-free areas of tips of cusps of unerupted molars, cilia of respiratory epithelium, and tissue macrophages. This distribution corresponds to the cellular sites of tartrate-resistant acid phosphatase activity, as revealed by enzyme histochemistry. With the ABC method, staining in osteoclasts was obtained with antiserum dilutions of up to 1:10,000. Biochemical studies revealed that vanadate-sensitive acid ATPase activity in liver subcellular fractions was almost exclusively confined to lysosomes. Thus, the immunostaining has revealed the presence of the tartrate-resistant and vanadate-sensitive nucleotide phosphatase in many cells associated with tissue resorption and phagocytosis.