Effects of capsaicin on IA and IK in cultured trigeminal ganglion neurons of rat.
- Author:
Hui FU
1
;
Hui LIU
;
Xue-hong CAO
;
Ji-zhou XIANG
;
Lie-ju LIU
Author Information
- Publication Type:Journal Article
- MeSH: Animals; Capsaicin; pharmacology; Cells, Cultured; Female; Male; Neurons; physiology; Patch-Clamp Techniques; Potassium Channels, Voltage-Gated; drug effects; Rats; Rats, Sprague-Dawley; Trigeminal Ganglion; cytology; physiology
- From: Acta Pharmaceutica Sinica 2004;39(12):975-979
- CountryChina
- Language:Chinese
-
Abstract:
AIMTo investigate the effect of capsaicin on IA and IK in cultured rat trigeminal ganglion (TG) neurons.
METHODSWhole-cell patch clamp technique was used to record the IA and IK before and after capsaicin perfusion at different concentrations.
RESULTSIn capsaicin-sensitive (CS) neurons, capsaicin was shown to selectively inhibit IA in dose-dependent manner, the IC50 was 0.99 micromol x L(-1). Yet capsaicin showed no inhibitory effect on IK, capsaicin (10 micromol x L(-1)) only slightly inhibited IK by 13.2%. In capsaicin-insensitive (CIS) neurons, capsaicin (1 micromol x L(-1)) showed no significant inhibitory effect on IA and IK, capsaicin (10 micromol x L(-1)) only slightly inhibited IA and IK by 16.8% and 15.3%, respectively. Neither 1 micromol x L(-1) nor 10 micromol x L(-1) capsaicin showed effect on the G-V curve of IA and IK.
CONCLUSIONCapsaicin was found to selectively inhibit the IA current in CS neurons, and this effect may contribute to hyperalgesia when capsaicin was first used.
