|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
CELLULAR |
1 From the Department of Pharmacology, Georgetown University, Washington, DC 20007, USA
Omega-3 (n-3) fatty acids are essential for proper neuronal function, and they possess prominent analgesic properties, yet their underlying signalling mechanisms are unclear. Here we show that n-3 fatty acids interact directly with TRPV1, an ion channel expressed in nociceptive neurones and brain. These fatty acids activate TRPV1 in a phosphorylation-dependent manner, enhance responses to extracellular protons, and displace binding of the ultrapotent TRPV1 ligand [3H]resiniferatoxin. In contrast to their agonistic properties, n-3 fatty acids competitively inhibit the responses of vanilloid agonists. These actions occur in mammalian cells in the physiological concentration range of 110 µM. Significantly, docosahexaenoic acid exhibits the greatest efficacy as an agonist, whereas eicosapentaenoic acid and linolenic acid are markedly more effective inhibitors. Similarly, eicosapentaenoic acid but not docosahexaenoic acid profoundly reduces capsaicin-evoked pain-related behaviour in mice. These effects are independent of alterations in membrane elasticity because the micelle-forming detergent Triton X-100 only minimally affects TRPV1 properties. Thus, n-3 fatty acids differentially regulate TRPV1 and this form of signalling may contribute to their biological effects. Further, these results suggest that dietary supplementation with selective n-3 fatty acids would be most beneficial for the treatment of pain.
(Received 28 September 2006;
accepted after revision 8 October 2006;
first published online 12 October 2006)
Corresponding author G. P. Ahern: Department of Pharmacology, Georgetown University, MedDent SW401, 3900 Reservoir Rd, Washington, DC 20007, USA. Email: gpa3{at}georgetown.edu
This article has been cited by other articles:
![]() |
P. M. Cornett, J. A. Matta, and G. P. Ahern General Anesthetics Sensitize the Capsaicin Receptor Transient Receptor Potential V1 Mol. Pharmacol., November 1, 2008; 74(5): 1261 - 1268. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. A. Lundbaek Lipid Bilayer-mediated Regulation of Ion Channel Function by Amphiphilic Drugs J. Gen. Physiol., May 1, 2008; 131(5): 421 - 429. [Full Text] [PDF] |
||||
![]() |
J. A. Matta and G. P. Ahern Voltage is a partial activator of rat thermosensitive TRP channels J. Physiol., December 1, 2007; 585(2): 469 - 482. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. J. Bruno, R. E. Koeppe II, and O. S. Andersen Docosahexaenoic acid alters bilayer elastic properties PNAS, June 5, 2007; 104(23): 9638 - 9643. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |