The discharge of primary and secondary granules during immune phagocytosis by normal and chronic granulocytic leukaemia polymorphonuclear neutrophils.

The two types of granule in polymorphonuclear neutrophils may have distinct functions. The primary granule enzymes are responsible for killing and digesting ingested micro-organisms while the secondary granule constituents may have regulatory functions outside the cell. This hypothesis is supported by finding that during immune phagocytosis of a yeast, nearly all of the neutrophil's secondary granule vitamin B12-binding protein is lost from the cell and 80% can be accounted for in the medium. Much less of the primary granule enzymes, beta-glucuronidase and acid phosphatase, are lost from the cells and very little can be detected in the medium. Lysozyme is a constituent of both types of granule and its behaviour is intermediate. There is no difference in the release of these granule constituents from chronic granulocytic leukaemia neutrophils compared with normal neutrophils.