Immunohistochemical study of phospholipase A2 in bovine prostate.

Approximately 1,100-fold purified phospholipase A2 (PLA2) from bovine prostate was injected into rabbit to prepare polyclonal antibodies. Antibodies produced showed specific immunoprecipitation only with the purified enzyme, as well as with homogenate of bovine prostatic tissue. By Western blot analysis or by immunodiffusion test, no cross-reactivity with PLA2 purified from human seminal plasma, bovine pancreas, Crotalus adamanteus venom, or with partially purified PLA2 from bovine seminal vesicle fluid or Cowper's glands was observed. Using the indirect peroxidase technique, PLA2 was localized in the cytoplasm of bovine prostatic epithelial cells. By immunogold microscopy, this enzyme was directly visualized inside the lysosomes, as well as in the endoplasmic reticulum of the glandular epithelial cells. Enzyme activity was localized in two principal subcellular sites: the mitochondria and lysosome-enriched fraction, and in the microsomal fraction.