Signaling mechanisms of down-regulation of voltage-activated Ca2+ channels by transient receptor potential vanilloid type 1 stimulation with olvanil in primary sensory neurons

Neuroscience. 2006 Aug 11;141(1):407-19. doi: 10.1016/j.neuroscience.2006.03.023. Epub 2006 May 6.


Olvanil ((N-vanillyl)-9-oleamide), a non-pungent transient receptor potential vanilloid type 1 agonist, desensitizes nociceptors and alleviates pain. But its molecular targets and signaling mechanisms are little known. Calcium influx through voltage-activated Ca(2+) channels plays an important role in neurotransmitter release and synaptic transmission. Here we determined the effect of olvanil on voltage-activated Ca(2+) channel currents and the signaling pathways in primary sensory neurons. Whole-cell voltage-clamp recordings were performed in acutely isolated rat dorsal root ganglion neurons. Olvanil (1 microM) elicited a delayed but sustained inward current, and caused a profound inhibition (approximately 60%) of N-, P/Q-, L-, and R-type voltage-activated Ca(2+) channel current. Pretreatment with a specific transient receptor potential vanilloid type 1 antagonist or intracellular application of 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid abolished the inhibitory effect of olvanil on voltage-activated Ca(2+) channel current. Calmodulin antagonists (ophiobolin-A and calmodulin inhibitory peptide) largely blocked the effect of olvanil and capsaicin on voltage-activated Ca(2+) channel current. Furthermore, calcineurin (protein phosphatase 2B) inhibitors (deltamethrin and FK-506) eliminated the effect of olvanil on voltage-activated Ca(2+) channel current. Notably, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, calmodulin antagonists, and calcineurin inhibitors each alone significantly increased the amplitude of voltage-activated Ca(2+) channel current. In addition, double immunofluorescence labeling revealed that olvanil induced a rapid internalization of Ca(V)2.2 immunoreactivity from the membrane surface of dorsal root ganglion neurons. Collectively, this study suggests that stimulation of non-pungent transient receptor potential vanilloid type 1 inhibits voltage-activated Ca(2+) channels through a biochemical pathway involving intracellular Ca(2+)-calmodulin and calcineurin in nociceptive neurons. This new information is important for our understanding of the signaling mechanisms of desensitization of nociceptors by transient receptor potential vanilloid type 1 analogues and the feedback regulation of intracellular Ca(2+) and voltage-activated Ca(2+) channels in nociceptive sensory neurons.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Aryldialkylphosphatase / pharmacology
  • Calcium Channels / physiology*
  • Calcium Channels, N-Type / metabolism
  • Capsaicin / analogs & derivatives*
  • Capsaicin / pharmacology
  • Chelating Agents / pharmacology
  • Diterpenes / pharmacology
  • Dose-Response Relationship, Radiation
  • Drug Interactions
  • Egtazic Acid / analogs & derivatives
  • Egtazic Acid / pharmacology
  • Electric Stimulation / methods
  • Enzyme Inhibitors / pharmacology
  • Ganglia, Spinal / cytology
  • Immunohistochemistry / methods
  • Male
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • Membrane Potentials / radiation effects
  • Neural Inhibition / drug effects
  • Neural Inhibition / radiation effects
  • Neurons, Afferent / drug effects*
  • Neurons, Afferent / radiation effects
  • Patch-Clamp Techniques / methods
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects*
  • TRPV Cation Channels / agonists*
  • TRPV Cation Channels / antagonists & inhibitors
  • TRPV Cation Channels / metabolism
  • TRPV Cation Channels / physiology


  • Cacna1b protein, rat
  • Calcium Channels
  • Calcium Channels, N-Type
  • Chelating Agents
  • Diterpenes
  • Enzyme Inhibitors
  • TRPV Cation Channels
  • Trpv1 protein, rat
  • iodoresiniferatoxin
  • olvanil
  • Egtazic Acid
  • Aryldialkylphosphatase
  • 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid
  • Capsaicin