Intracellular calcium redistribution and its relationship to fMet-Leu-Phe, leukotriene B4, and phorbol ester induced rabbit neutrophil degranulation
✍ Scribed by P. H. Naccache; T. F. P. Molski; P. Borgeat; R. I. Sha'afi
- Publisher
- John Wiley and Sons
- Year
- 1985
- Tongue
- English
- Weight
- 773 KB
- Volume
- 122
- Category
- Article
- ISSN
- 0021-9541
No coin nor oath required. For personal study only.
✦ Synopsis
The addition of low concentrations (<lo-' M ) of the calcium ionophore A23187 to rabbit neutrophils releases t h e intracellular pool of calcium previously shown in radioactive steady-state and chlortetracycline fluorescence studies to be mobilized by chemotactic factors. A23187 at these concentrations elicits no functional responses from these cells. However, A23187, added before chemotactic factors such as fMet-Leu-Phe and leukotriene B4, inhibits the ability of the latter stimuli to induce, in the presence of cytochalasin B, an exocytotic release of the neutrophil's cytoplasmic granules. These results imply that the chemotactic-factor-induced release of intracellular calcium is a necessary event for the optimal activation of t h e neutrophils. Phorbol esterinduced neutrophil degranulation on the other hand is unaffected by exposure to A23187, thereby completely dissociating its mechanism of action from rises in cytoplasmic free calcium.
(PMA), a compound that appears to activate neutrophils independently of the presence of extracellular calcium (Becker et al., 1981) or of a rise in cytoplasmic free