Abstract
Previous studies of human basophil mediator release have noted that the bacterial peptide fmet-leu-phe and the anaphylatoxin C5a induce comparable levels of histamine release while only fmet peptide induces leukotriene release. Since 5-lipoxygenase metabolism of arachidonic acid is calcium dependent, we examined the characteristics of the human basophil [Ca++](i) response which folows its activation by either fmet peptide or C5a. While the peak [Ca++](i) response was essentially identical for these two stimuli, fmet peptide induced a prolonged increase in [Ca++](i) while C5a stimulated only a transient increase in [Ca++](i) that was essentially over within 2 minutes of adding the stimulus. Simultaneous addition of EDTA with fmet peptide revealed the two phases of the [Ca++](i) response and demonstrated that leukotriene release was dependent on an elevated [Ca++](i) level in the 2-5 minutes following challenge. Enhancement of leukotriene release induced by C5a by agents such as staurosporine and interleukin-3 also produced a [Ca++](i) kinetic curve which resembled fmet peptide. Single cell studies of the [Ca++](i) response could detect no subpopulations of cells which responded preferentially to fmet peptide or C5a, eliminating the possibility that the ability of fmet peptide to induce leukotriene was a result of its action on a functionally distinct population of basophils.
Original language | English (US) |
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Pages (from-to) | 29-40 |
Number of pages | 12 |
Journal | Journal of Leukocyte Biology |
Volume | 49 |
Issue number | 1 |
DOIs | |
State | Published - 1991 |
Keywords
- Calcium
- Interleukin-3
- Staurosporine
ASJC Scopus subject areas
- Immunology and Allergy
- Immunology
- Cell Biology