Cross-talk between calcium and cAMP-dependent intracellular signaling pathways: Implications for synergistic secretion in T84 colonic epithelial cells and rat pancreatic acinar cells

Mana Vajanaphanich, Carsten Schultz, Roger Y. Tsien, Alexis E. Traynor-Kaplan, Stephen J. Pandol, Kim E. Barrett

Research output: Contribution to journalArticle

50 Scopus citations

Abstract

Treatment of various cells with combinations of agents that increase either cAMP or cytosolic calcium can lead to synergistic responses. This study examined interactions, or cross-talk, between these two intracellular messengers and its implication for signaling in two secretory cell types, T84 human colonic epithelial cells and rat pancreatic acinar cells. T84 cell chloride secretion was measured in Ussing chambers. Acinar cell activation was monitored as amylase secretion. Cytosolic calcium was assessed via fura-2 microfluorimetry. A cell-permeant analogue of cAMP synergistically enhanced secretory responses to calcium-mobilizing hormones in both cell types, but paradoxically reduced overall calcium mobilization. The reduction in calcium mobilization could be attributed to an inhibition of calcium influx in T84 cells, although a different mechanism likely operates in acinar cells. The effects of the cAMP analogue were reproduced by other agents that increase cAMP. Furthermore, econazole, an inhibitor of calcium influx, potentiated secretory responses to calcium-dependent stimulation in T84 cells without itself inducing secretion. We conclude that there is cross-talk between calcium and cAMP-dependent signaling pathways at the level of second messenger generation in two secretory cell types. This cross-talk appears to regulate the extent of secretory responses.

Original languageEnglish (US)
Pages (from-to)386-393
Number of pages8
JournalJournal of Clinical Investigation
Volume96
Issue number1
DOIs
StatePublished - Jul 1995

Keywords

  • Amylase secretion
  • Chloride secretion
  • Exocytosis
  • Signal transduction

ASJC Scopus subject areas

  • Medicine(all)

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