Selective activation of G-protein coupled receptors by volatile anesthetics

Mol Cell Neurosci. 2005 Dec;30(4):506-12. doi: 10.1016/j.mcn.2005.08.012. Epub 2005 Sep 26.

Abstract

Ion channels and ionotropic neurotransmitter receptors have long been investigated as the principle targets of inhaled volatile anesthetics (VAs), but emerging evidence suggests that G-protein coupled receptors (GPCRs) might also directly interact with VAs. To survey the extent of interaction between VAs and diverse GPCRs, we have turned to the 1000+ member family of olfactory receptors (ORs), taking advantage of their unique expression pattern of a single OR per neuron. Through optical imaging and electrophysiological recordings, we show that different VAs trigger the normal transduction cascade in distinct subsets of cells in a dose-dependant manner. Together with evidence of antagonism by odorants, this selective activation strongly implicates a direct action of VAs upon particular olfactory receptors. The finding that VAs stimulate nearly 8% of olfactory GPCRs suggests that probing related Class A GPCRs may reveal a pool of VA targets whose altered signaling contributes to anesthetic effects.

MeSH terms

  • Anesthetics, Inhalation / pharmacology*
  • Animals
  • Dose-Response Relationship, Drug
  • Halothane / pharmacology
  • In Vitro Techniques
  • Male
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • Octanols / pharmacology
  • Odorants
  • Olfactory Mucosa / drug effects*
  • Olfactory Mucosa / metabolism
  • Olfactory Receptor Neurons / drug effects*
  • Olfactory Receptor Neurons / metabolism
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, G-Protein-Coupled / drug effects*
  • Receptors, G-Protein-Coupled / metabolism
  • Receptors, Odorant / drug effects*
  • Receptors, Odorant / metabolism
  • Signal Transduction / drug effects
  • Signal Transduction / physiology
  • Smell / drug effects
  • Smell / physiology

Substances

  • Anesthetics, Inhalation
  • Octanols
  • Receptors, G-Protein-Coupled
  • Receptors, Odorant
  • Halothane