|
|
||||||||
The responses of vanilloid receptor (VR) channels to changing membrane potential were studied in Xenopus oocytes and rat dorsal root ganglion (DRG) neurons. In oocytes, capsaicin-evoked VR currents increased instantaneously upon a step depolarization and thereafter rose biexponentially with time constants of ~20 and 1000 ms. Similarly, upon repolarization the current abruptly decreased, followed by a biexponential decay with time constants of ~4 and 200 ms. Qualitatively similar effects were observed in single channel recordings of native VR channels from DRG neurons and with endogenous VR activators, including heat (43 °C), H+, anandamide and protein kinase C (PKC). The magnitude of the time-dependent current rise increased with membrane depolarization. This effect was accompanied by an increase in the relative proportion of the fast kinetic component, A1. In contrast, the time constants of the activation and deactivation processes were not strongly voltage dependent. Increasing the agonist concentration both reduced the magnitude of the current rise and increased its overall rate, without significantly altering the deactivation rate. In contrast, PKC both speeded the current rise and slowed its decay. These results suggest that voltage interacts with agonists in a synergistic manner to augment VR current and this mechanism will be enhanced under conditions of inflammation when VRs are likely to be phosphorylated.
This article has been cited by other articles:
![]() |
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] |
||||
![]() |
J. A. Matta, R. L. Miyares, and G. P. Ahern TRPV1 is a novel target for omega-3 polyunsaturated fatty acids J. Physiol., January 15, 2007; 578(2): 397 - 411. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Xu, N. T. Blair, and D. E. Clapham Camphor Activates and Strongly Desensitizes the Transient Receptor Potential Vanilloid Subtype 1 Channel in a Vanilloid-Independent Mechanism J. Neurosci., September 28, 2005; 25(39): 8924 - 8937. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Nilius, K. Talavera, G. Owsianik, J. Prenen, G. Droogmans, and T. Voets Gating of TRP channels: a voltage connection? J. Physiol., August 15, 2005; 567(1): 35 - 44. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Weil, S. E. Moore, N. J. Waite, A. Randall, and M. J. Gunthorpe Conservation of Functional and Pharmacological Properties in the Distantly Related Temperature Sensors TRVP1 and TRPM8 Mol. Pharmacol., August 1, 2005; 68(2): 518 - 527. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. P. Ahern, I. M. Brooks, R. L. Miyares, and X.-b. Wang Extracellular Cations Sensitize and Gate Capsaicin Receptor TRPV1 Modulating Pain Signaling J. Neurosci., May 25, 2005; 25(21): 5109 - 5116. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Jin, N. Morsy, J. Winston, P. J. Pasricha, K. Garrett, and H. I. Akbarali Modulation of TRPV1 by nonreceptor tyrosine kinase, c-Src kinase Am J Physiol Cell Physiol, August 1, 2004; 287(2): C558 - C563. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Amadesi, J. Nie, N. Vergnolle, G. S. Cottrell, E. F. Grady, M. Trevisani, C. Manni, P. Geppetti, J. A. McRoberts, H. Ennes, et al. Protease-Activated Receptor 2 Sensitizes the Capsaicin Receptor Transient Receptor Potential Vanilloid Receptor 1 to Induce Hyperalgesia J. Neurosci., May 5, 2004; 24(18): 4300 - 4312. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |