Axon Reflexes Evoked by Transient Receptor Potential Vanilloid 1 Activation Are Mediated by Tetrodotoxin-Resistant Voltage-Gated Na+ Channels in Intestinal Afferent Nerves

2010 ◽  
Vol 334 (2) ◽  
pp. 566-575 ◽  
Author(s):  
M. Miranda-Morales ◽  
F. Ochoa-Cortes ◽  
E. Stern ◽  
A. E. Lomax ◽  
S. Vanner
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Na Channels ◽  
Voltage Gated ◽  
Afferent Nerves ◽  
Transient Receptor

scholarly journals Beyond Hot and Spicy: TRPV Channels and their Pharmacological Modulation

2021 ◽  
Vol 55 (S3) ◽  
pp. 108-130
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Transmembrane Helices ◽  
Endogenous Ligands ◽  
Voltage Gated ◽  
Kv Channels ◽  
Trpv Channels ◽  
Transient Receptor ◽  
Pain Stimuli

Transient receptor potential vanilloid (TRPV) channels are part of the TRP channel superfamily and named after the first identified member TRPV1, that is sensitive to the vanillylamide capsaicin. Their overall structure is similar to the structure of voltage gated potassium channels (Kv) built up as homotetramers from subunits with six transmembrane helices (S1-S6). Six TRPV channel subtypes (TRPV1-6) are known, that can be subdivided into the thermoTRPV (TRPV1-4) and the Ca2+-selective TRPV channels (TRPV5, TRPV6). Contrary to Kv channels, TRPV channels are not primary voltage gated. All six channels have distinct properties and react to several endogenous ligands as well as different gating stimuli such as heat, pH, mechanical stress, or osmotic changes. Their physiological functions are highly diverse and subtype as well as tissue specific. In many tissues they serve as sensors for different pain stimuli (heat, pressure, pH) and contribute to the homeostasis of electrolytes, the maintenance of barrier functions and the development of macrophages. Due to their fundamental role in manifold physiological and pathophysiological processes, TRPV channels are promising targets for drug development. However, drugs targeting specific TRPV channels, that are suitable for drug therapy, are rare. Moreover, selective and potent compounds for further research at TRPV channels are often lacking. In this review different aspects of the structure, the different gating stimuli, the expression pattern, the physiological and pathophysiological roles as well as the modulating mechanisms of synthetic, natural and endogenous ligands are summarized.

scholarly journals Eugenol Inhibits K+ Currents in Trigeminal Ganglion Neurons

2007 ◽  
Vol 86 (9) ◽  
pp. 898-902 ◽  
Author(s):  
H.Y. Li ◽  
C.-K. Park ◽  
S.J. Jung ◽  
S.-Y. Choi ◽  
S.J. Lee ◽  
...  
Keyword(s):  
Trigeminal Ganglion ◽  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Inhibitory Effects ◽  
Independent Manner ◽  
Voltage Gated ◽  
Trigeminal Ganglion Neurons ◽  
Transient Receptor ◽  
Ganglion Neurons

Eugenol, a natural capsaicin congener, is widely used in dentistry. Eugenol inhibits voltage-activated Na+ and Ca2+ channels in a transient receptor potential vanilloid 1 (TRPV1)-independent manner. We hypothesized that eugenol also inhibits voltage-gated K+ currents, and investigated this in rat trigeminal ganglion neurons and in a heterologous system using whole-cell patch clamping. Eugenol inhibited voltage-gated K+ currents, and the inhibitory effects of eugenol were observed in both capsaicin-sensitive and capsaicin-insensitive neurons. Pre-treatment with capsazepine, a well-known antagonist of TRPV1, failed to block the inhibitory effects of eugenol on K+ currents, suggesting no involvement of TRPV1. Eugenol inhibited human Kv1.5 currents stably expressed in Ltk− cells, where TRPV1 is not endogenously expressed. We conclude that eugenol inhibits voltage-gated K+ currents in a TRPV1-independent manner. The inhibition of voltage-gated K+ currents is likely to contribute to the irritable action of eugenol. Abbreviations: human Kv1.5 channel, hKv1.5; transient receptor potential vanilloid 1, TRPV1.

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