The distribution of peroxidase in phagocytizing human blood platelets, electron microscopy findings

On the basis of a previously elaborated method for testing the phagocytic ability of human blood platelets we have undertaken studies for testing the distribution of peroxidase in phagocytizing platelets. Our findings confirmed the distribution of peroxidase in the dense tubular system and in granules in regular blood platelets. In the course of phagocytosis we noted the presence of peroxidase less evidently in both subcellular structures during the first of 5 minutes. In the next steps we observed the localization of this enzyme mainly near the phagolysosome. The change of this localization and the role of this enzyme in unspecific immunity against bacteria and neoplasia is briefly discussed.