Intracellular or extracellular calcium can be used to trigger C5a-stimulated enzyme secretion from rabbit neutrophils

Connie L. Stapleton, Ronald M. Barnard, Douglas E. Chandler

Research output: Contribution to journalArticle

4 Scopus citations


The ability of C5a to stimulate lysosomal enzyme release and 45Ca2+ efflux from rabbit neutrophils was studied. C5a stimulated β-glucuronidase release from cytochalasin B-treated neutrophils either in the presence or absence of extracellular calcium. Depletion of cell calcium by pretreatment with the calcium ionophore A23187 blocked both the ability of C5a to elicit enzyme release in the absence of extracellular calcium and its ability to stimulate 45Ca2+ efflux. Both actions were dose-dependent over the same concentration range (10-8-10-6 M ionophore A23187). In contrast, ionophore pretreatment had no effect on C5a-stimulated enzyme release in the presence of extracellular calcium. These results suggest that (a) release of cell calcium is required for enzyme secretion in the absence of extracellular calcium, and (b) C5a can trigger near-maximal enzyme release by using calcium from either of two sources: the extracellular space or an intracellular site.

Original languageEnglish (US)
Pages (from-to)225-230
Number of pages6
JournalBBA - Molecular Cell Research
Issue number3
Publication statusPublished - Oct 25 1983



  • (Rabbit neutrophil)
  • C5a
  • Ca
  • Complement component
  • Enzyme secretion
  • Ionophore A23187
  • Stimulus-secretion coupling

ASJC Scopus subject areas

  • Biophysics
  • Cell Biology
  • Molecular Biology

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