Studies on crystal-induced chemotactic factor. II. Role of phagocytosis

The interaction of polymorphonuclear leukocytes (PMN's) and urate crystal leads to the formation of a chemotactic factor. The purpose of this study was to determine the need for ingestion of crystals by the cells in the generation of the chemotactic factor. Our studies showed that when PMN's were incubated with cytochalasin B, an inhibitor of phagocytosis, and urate crystals, no chemotactic activity appeared in the lysosomal extract of the cells. Likewise, no chemotactic activity was present in the media of PMN's incubated with crystals although lysosomal enzyme activity was increased. These findings indicate that phagocytosis is required for chemotactic activity to appear. Our studies also show that cytochalasin B increases the release of lysosomal enzyme B-glucuronidase but not of cytoplasmic enzyme lactic dehydrogenase from PMN's when the cell encounters urate crystals.