Exocytosis of granule constituents in response to stimulation
| . | Control neutrophils . | Exudate neutrophils . | ||||
|---|---|---|---|---|---|---|
| MPO . | hCAP-18 . | Gelatinase . | MPO . | hCAP-18 . | Gelatinase . | |
| No addition | 0.8 (34) | 0.9 (29) | 1.6 | 4.2 (187) | 13.4 (316) | 24.1 |
| fMLP (10−8M) | 2.3 (66) | 5.2 (153) | 31.0 | 9.6 (274) | 15.5 (387) | 49.9 |
| Immunoglobulin-coated latex beads | 14.3 (354) | 10.4 (272) | 45.3 | 17.1 (268) | 27.8 (309) | 63.7 |
| Ionomycin (1 μM) | 34.9 (924) | 64.3 (2415) | 88.8 | 11.9 (560) | 65.5 (1658) | 92.9 |
| . | Control neutrophils . | Exudate neutrophils . | ||||
|---|---|---|---|---|---|---|
| MPO . | hCAP-18 . | Gelatinase . | MPO . | hCAP-18 . | Gelatinase . | |
| No addition | 0.8 (34) | 0.9 (29) | 1.6 | 4.2 (187) | 13.4 (316) | 24.1 |
| fMLP (10−8M) | 2.3 (66) | 5.2 (153) | 31.0 | 9.6 (274) | 15.5 (387) | 49.9 |
| Immunoglobulin-coated latex beads | 14.3 (354) | 10.4 (272) | 45.3 | 17.1 (268) | 27.8 (309) | 63.7 |
| Ionomycin (1 μM) | 34.9 (924) | 64.3 (2415) | 88.8 | 11.9 (560) | 65.5 (1658) | 92.9 |
Isolated neutrophils were incubated with or without stimulus. Exocytosis of granule proteins was determined by ELISA measurements. MPO was chosen as a marker for azurophil granules, hCAP-18 for specific granules, and gelatinase for gelatinase granules. Exocytosis is expressed as percentage of total amounts in the cells and medium. Absolute concentrations (ng/mL) of MPO and hCAP-18 are given in parentheses. It should be noted that although the release of MPO from ionomycin-stimulated exudate neutrophils was lower in terms of percentage of total amount than that from exudate cells stimulated with latex beads, the release of MPO was highest in the ionomycin-stimulated cells in terms of absolute concentration of released MPO.
MPO indicates myeloperoxidase; fMLP, formyl methionyleucylphenylalanine; ELISA, enzyme-linked immunosorbent assay.