Complement component C9-dependent cytosolic free Ca2+ rise and recovery in neutrophils.
Cell Calcium
; 17(4): 279-86, 1995 Apr.
Article
em En
| MEDLINE
| ID: mdl-7664315
ABSTRACT
The cytosolic free Ca2+ concentration in rat neutrophils was determined by ratiometric fluorometry and imaging of Fura-2. Transient elevations of cytosolic free Ca2+ concentration were provoked by addition of C9 to neutrophils pre-coated with C5b-8. The rate of rise of the cytosolic free Ca2+ concentration was dependent upon the concentration of C9. These changes in cytosolic free Ca2+ concentration occurred in the absence of cell lysis, since there was no release of Fura-2, and were the result of increased permeability to extracellular Ca2+. More than 96% of the rise in cytosolic free Ca2+ generation by C9 was dependent upon the presence of extracellular Ca2+, but did not occur via channels which were inhibited by the Ca2+ channel blocker SKF96365. The decrease in the permeability of the membrane to Ca2+ after C9 was not triggered by the rise in cytosolic free Ca2+. After attack by C9, individual neutrophils remained responsive to f-met-leu-phe, or further attack by C9, both producing Ca2+ transients. The recovery of the Ca2+ signal was consistent with the complement membrane attack complex generating a series of permeability thresholds in the plasma membrane. These data have implications for the understanding of the mechanisms underlying the inappropriate responsiveness of neutrophils at inflammatory sites.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cálcio
/
Diamino Aminoácidos
/
Aminoácidos Dicarboxílicos
/
Imidazóis
/
Neutrófilos
Limite:
Animals
Idioma:
En
Revista:
Cell Calcium
Ano de publicação:
1995
Tipo de documento:
Article
País de afiliação:
Reino Unido