Functional coupling of secretion and capacitative calcium entry in PC12 cells

Biochem Biophys Res Commun. 1998 Mar 6;244(1):293-7. doi: 10.1006/bbrc.1998.8251.


The caffeine-evoked effects on the intracellular Ca2+ concentration ([Ca2+]i) and on the release of dopamine by PC12 cells were investigated. Stimulation by caffeine resulted in a transient Ca2+ release which was followed by a sustained phase of Ca2+ entry through a non-voltage dependent pathway. Treatment with cyclopiazonic acid (CPA) or thapsigargin, inhibitors of the Ca2+ ATPase pump of the endoplasmic reticulum, resulted in only a sustained rise in [Ca2+]i in the presence of extracellular Ca2+. Pretreatment of cells with CPA or thapsigargin abolished the subsequent Ca2+ responses to caffeine. Caffeine also evoked the release of dopamine from the cells only in the presence of extracellular Ca2+, which was mimicked by CPA. These results suggest that store-dependent Ca2+ entry evoked by caffeine has an indispensable role in the secretory response in an excitable cell line, PC12 cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caffeine / pharmacology
  • Calcium / antagonists & inhibitors
  • Calcium / physiology*
  • Calcium Channel Blockers / pharmacology
  • Calcium Channels / physiology*
  • Cations, Divalent
  • Dopamine / metabolism
  • Exocytosis / physiology
  • Extracellular Space / physiology
  • Indoles / pharmacology
  • Intracellular Fluid / physiology
  • PC12 Cells
  • Rats
  • Signal Transduction / physiology*
  • Theophylline / pharmacology
  • Zinc / pharmacology


  • Calcium Channel Blockers
  • Calcium Channels
  • Cations, Divalent
  • Indoles
  • Caffeine
  • Theophylline
  • Zinc
  • Calcium
  • Dopamine
  • cyclopiazonic acid