Zn2+ potentiates ATP-activated currents in rat sympathetic neurons

Pflugers Arch. 1993 Jul;424(2):152-8. doi: 10.1007/BF00374606.


The ATP-activated inward current (IATP) in cultured rat superior cervical ganglion neurons and its modulation by extracellular Zn2+ were examined. ATP activated a non-specific cation conductance and caused a transient rise in intracellular Ca2+. The current response was specifically activated by ATP and was blocked by the P2-purinoceptor antagonist, suramin. Low concentrations of extracellular Zn2+ rapidly and reversibly potentiated both IATP and the intracellular Ca2+ rise. The potentiation by 10 microM Zn2+ was dependent on the concentration of agonist; Zn2+ increased the sensitivity of activation without potentiating the maximum response. Higher concentrations of Zn2+ reduced and prolonged the current, consistent with open-channel block. We hypothesize that there exist two sites of action for Zn2+: a positively acting allosteric site that enhances current amplitude and a site, possibly within the pore, that blocks conductance through the channel.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / pharmacology*
  • Animals
  • Calcium / metabolism
  • Cations, Divalent / pharmacology
  • Cells, Cultured
  • Electrophysiology
  • Ion Channel Gating / drug effects
  • Ion Channels / drug effects
  • Ion Channels / metabolism*
  • Neurons / drug effects
  • Neurons / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Purinergic P2 / drug effects
  • Superior Cervical Ganglion / cytology
  • Superior Cervical Ganglion / drug effects
  • Superior Cervical Ganglion / metabolism
  • Suramin / pharmacology
  • Sympathetic Nervous System / cytology
  • Sympathetic Nervous System / drug effects
  • Sympathetic Nervous System / metabolism*
  • Zinc / pharmacology*


  • Cations, Divalent
  • Ion Channels
  • Receptors, Purinergic P2
  • Suramin
  • Adenosine Triphosphate
  • Zinc
  • Calcium