A rapid capsaicin-activated current in rat trigeminal ganglion neurons.

Published

Journal Article

A subpopulation of pain fibers are activated by capsaicin, the ingredient in red peppers that produces a burning sensation when eaten or placed on skin. Previous studies on dorsal root ganglion neurons indicated that capsaicin activates sensory nerves via a single slowly activating and inactivating inward current. In rat trigeminal neurons, we identified a second capsaicin-activated inward current. This current can be distinguished from the slow one in that it rapidly activates and inactivates, requires Ca2+ for activation, and is insensitive to the potent capsaicin agonist resiniferatoxin. The rapid current, like the slower one, is inhibited by ruthenium red and capsazepine. The two capsaicin-activated inward currents share many similarities with the two inward currents activated by lowering the pH to 6.0. These similarities include kinetics, reversal potentials, responses to Ca2+, and inhibition by ruthenium red and capsazepine. These results suggest that acidic stimuli may be an endogenous activator of capsaicin-gated currents and therefore may rationalize why pain is produced when the plasma acidity is increased, as occurs during ischemia and inflammation.

Full Text

Duke Authors

Cited Authors

  • Liu, L; Simon, SA

Published Date

  • January 18, 1994

Published In

Volume / Issue

  • 91 / 2

Start / End Page

  • 738 - 741

PubMed ID

  • 8290592

Pubmed Central ID

  • 8290592

International Standard Serial Number (ISSN)

  • 0027-8424

Digital Object Identifier (DOI)

  • 10.1073/pnas.91.2.738

Language

  • eng

Conference Location

  • United States