Korean J Physiol Pharmacol.  2007 Oct;11(5):215-219.

Mechanical Hyperalgesia Induced by Blocking Calcium-activated Potassium Channels on Capsaicin-sensitive Afferent Fiber

• Lee KH
• Shin HK

Abstract

Small and large conductance Ca2+-activated K+ (SKCa and BKCa) channels are implicated in the modulation of neuronal excitability. We investigated how changes in peripheral KCa channel activity affect mechanical sensitivity as well as the afferent fiber type responsible for KCa channel-induced mechanical sensitivity. Blockade of SKCa and BKCa channels induced a sustained decrease of mechanical threshold which was significantly attenuated by topical application of capsaicin onto afferent fiber and intraplantar injection of 1-ethyl-2-benzimidazolinone. NS1619 selectively attenuated the decrease of mechanical threshold induced by charybdotoxin, but not by apamin. Spontaneous flinching and paw thickness were not significantly different after KCa channel blockade. These results suggest that mechanical sensitivity can be modulated by KCa channels on capsaicin-sensitive afferent fibers.

Keyword

Ca2+-activated K+ channel; Mechanical sensitivity; Capsaicin-sensitive primary afferent fiber

MeSH Terms

Apamin
Capsaicin
Charybdotoxin
Hyperalgesia*
Neurons
Potassium Channels, Calcium-Activated*
Apamin
Capsaicin
Charybdotoxin
Potassium Channels, Calcium-Activated