Competitive inhibition of the glycine-induced current by pregnenolone sulfate in cultured chick spinal cord neurons

Brain Res. 1997 Mar 7;750(1-2):318-20. doi: 10.1016/s0006-8993(97)00053-x.


The effect of the neurosteroid pregnenolone sulfate (PS) on the glycine receptor-mediated response was studied in cultured chick spinal cord neurons using the whole-cell voltage-clamp recording technique. PS rapidly and reversibly inhibits the glycine-induced current in a dose-dependent manner, with an EC50 of 3.7 microM and a maximal inhibition of 100%. The fact that antagonism of the glycine response by PS is neither voltage- nor agonist-dependent indicates that PS does not act as an open-channel blocker. Furthermore, inhibition by PS of the glycine-induced current appears to be of a competitive type since the drug induces a parallel, rightward shift of the glycine dose-response curve.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Binding, Competitive
  • Cells, Cultured
  • Chick Embryo
  • Glycine / antagonists & inhibitors
  • Glycine / pharmacology*
  • Membrane Potentials / drug effects
  • Neurons / drug effects
  • Neurons / physiology*
  • Patch-Clamp Techniques
  • Pregnenolone / pharmacology*
  • Spinal Cord / physiology*


  • pregnenolone sulfate
  • Pregnenolone
  • Glycine