Calcium permeability of nicotinic acetylcholine receptor channels in bovine adrenal chromaffin cells

Pflugers Arch. 1993 Dec;425(5-6):511-7. doi: 10.1007/BF00374879.


The fractional contribution of Ca to current flow through neuronal-type nicotinic acetylcholine receptor channels was determined by quantitative fluorescence microfluorimetry using fura-2. The method, which has been applied already to several types of cells and channels is described in detail here. At -70 mV and 2 mM external Ca concentration it was found that Ca contributes 2.5% to the net current. The fractional contribution was found to be voltage dependent, increasing at negative potentials e-fold for a 110 mV potential difference. Total non-specific cation current was found to have a bell-shaped dependence on external Ca concentration peaking at 2 mM.

MeSH terms

  • Adrenal Glands / cytology
  • Adrenal Glands / metabolism*
  • Animals
  • Calcium / metabolism*
  • Calcium / pharmacology
  • Calcium / physiology
  • Calcium Channels / physiology
  • Cattle
  • Chromaffin System / cytology
  • Chromaffin System / metabolism*
  • Electrophysiology
  • Fura-2
  • Ion Channel Gating
  • Ion Channels / metabolism*
  • Permeability
  • Receptors, Nicotinic / metabolism*


  • Calcium Channels
  • Ion Channels
  • Receptors, Nicotinic
  • Calcium
  • Fura-2