Morphometric cytochemistry of catalase and myeloperoxidase-containing granules in the rabbit polymorphonuclear leukocyte.

Recently developed morphometric and statistical techniques were applied to the study of heterogeneity of the granule population of rabbit polymorphonuclear leukocytes. The cytochemical activities of myeloperoxidase and catalase were differentiated by incubation at pH 7.6, and pH 9.7 to 10.5, respectively. Each activity was found in more than one granule. Statistical evaluation suggested that in addition to the primary granule, two myeloperoxidase-containing granules and two catalase-containing granules existed. Although the presence of catalase activity has been described in the immature polymorphonuclear leukocyte previously, this is the first report indicating cytochemical reactivity in mature polymorphs.