Depolarization of rat basophilic leukemia cells inhibits calcium uptake and exocytosis

Frederick C Mohr, C. Fewtrell

Research output: Contribution to journalArticle

98 Citations (Scopus)

Abstract

We have investigated the unusual observation that depolarization of rat basophilic leukemia cells in high potassium not only fails to induce secretion, but also inhibits the secretion induced when receptors for IgE are aggregated by antigen. Antigen-stimulated 45Ca uptake and the rise in cytoplasmic free ionized calcium measured with the fluorescent indicator quin2 were both inhibited in depolarized cells. 45Ca efflux, on the other hand, was unaffected, which confirms that IgE receptor activation was not impaired in high potassium. Unlike the large increase in total cell calcium seen when cells in normal saline solution were stimulated with antigen, there was a decrease in total cell calcium when depolarized cells were stimulated. This is consistent with our finding that 45Ca uptake was inhibited while 45Ca efflux was unaffected. Inhibition of 45Ca uptake and secretion closely paralleled the decrease in membrane potential, and could be overcome by increasing the extracellular calcium concentration. We conclude that changes in the electrochemical gradient for calcium are important in determining calcium influx and the magnitude of antigen-stimulated secretion from rat basophilic leukemia cells, while the release of calcium from intracellular stores is unaffected.

Original languageEnglish (US)
Pages (from-to)783-792
Number of pages10
JournalJournal of Cell Biology
Volume104
Issue number3
StatePublished - 1987
Externally publishedYes

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Exocytosis
Leukemia
Calcium
IgE Receptors
Antigens
Potassium
Sodium Chloride
Membrane Potentials

ASJC Scopus subject areas

  • Cell Biology

Cite this

Depolarization of rat basophilic leukemia cells inhibits calcium uptake and exocytosis. / Mohr, Frederick C; Fewtrell, C.

In: Journal of Cell Biology, Vol. 104, No. 3, 1987, p. 783-792.

Research output: Contribution to journalArticle

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