A caffeine-sensitive Ca2+ store modulates K+-evoked secretion in chromaffin cells.

@article{Lara1997ACC,
  title={A caffeine-sensitive Ca2+ store modulates K+-evoked secretion in chromaffin cells.},
  author={Baldomero Lara and M. G. L{\'o}pez and M{\'e}rcedes Villarroya and Luis Gand{\'i}a and L. Cleeman and M. Morad and A. G. Garcı́a},
  journal={The American journal of physiology},
  year={1997},
  volume={272 4 Pt 1},
  pages={
          C1211-21
        }
}
Catecholamine release from bovine adrenal medulla chromaffin cells superfused with a Krebs-N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid solution was monitored on-line with an electrochemical detector. Caffeine (10 mM) progressively depressed the magnitude of secretory responses to depolarizing pulses of 70 mM K+ and 2 mM Ca2+ (70 K+/2 Ca2+) in cells superfused with a Krebs-N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid solution containing 0 mM Ca2+ + 0.5 mM EGTA; blockade reached 80… 
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Modulation of secretion by the endoplasmic reticulum in mouse chromaffin cells
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It is found that mouse chromaffin cells almost lack functional caffeine‐sensitive ryanodine receptors in the ER and, consistently, no CICR from the ER could be observed, and the ER strongly inhibits secretion by acting as a damper of the [Ca2+]c signal.
Q-type Ca2+ channels are located closer to secretory sites than L-type channels: functional evidence in chromaffin cells
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The results suggest that Q-type Ca2+ channels are coupled more tightly to exocytotic active sites, as compared to L-type channels.
Rundown of Secretion After Depletion of Intracellular Calcium Stores in Bovine Adrenal Chromaffin Cells
TLDR
It is suggested that brief elevations of [Ca2+]i could enhance subsequent secretory responses in control and thapsigargin‐treated cells, and that intracellular calcium stores are vital for the maintenance of exocytosis during repetitive stimulation.
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