Studies on the centrifugal fractionation of leukocyte granules, especially on the isolation of a pure fraction of neutrophilic granules and on the fine structure of neutrophilic granules as observed under the electron microscope.

Functionally active mature neutrophile leukocytes, generally are found to contain a few mitochondria, in extremely small number, either by supravital staining with Janus green, or by smear preparation and Altmann's staining process, and even with the electron microscope, a very few mitochondria may be observed. On the other hand, abundant neutrophilic granules may be found in neutrophile leukocytes. Up to now, the proposition, as to whether the energy metaboilsm of neutrophile leukocytes is inherent in neoplastic respiration 1> or in embryonic glycolysis, has remained unsolved. Recently, the metabolism of neutrophile leukocytes has been said to be inherent in aerobic glycolysis; 2> therefore, neutrophilic granules might play some important role in the mechanism of this peculiar metabolism of neutrophils, differing from that of the other cells in the body. Further, some studies 3> •> 5> have been made on eosinophilic granules, and to-date they have been isolated and analysed for chemical composition, but no research has yet been reported on neutrophilic granules, and the chemical components and the function or functions of the neutrophilic granules thus remain practically unknown. Finally, in order to investigate the properties of neutrophilic granules, the isolation of these granules was attempted. The possibility of fractionating the homogenate of leukocytes by differential centrifugation and of obtaining such frations as, nuclei, eosinophilic granules, mitochondria, neutrophilic granules, and microsomes, has already been reported in previous papers.6l 7> 8> At that time it was demonstrated by observation of the various fractions with an electron microscope, that almost pure neutrophilic granules could be obtained if the fractionating technique could be improved. Hence, in t his paper, a detailed account of the fractionation and technique of isolation, and of the fine structure of the isolated granules, will be reported.