Modulation of CaV2.3 calcium channel currents by eugenol.
Eugenol, a natural congener of capsaicin, is a routine analgesic agent in dentistry. We have recently demonstrated the inhibition of Ca(V)2.2 calcium channel and sodium channel currents to be molecular mechanisms underlying the analgesic effect of eugenol. We hypothesized that Ca(V)2.3 channels are also modulated by eugenol and investigated its mode of action using the whole-cell patch-clamp technique in a heterologous expression system. Eugenol inhibited calcium currents in the E52 cell line, stably expressing the human Ca(V)2.3 calcium channels, where TRPV1 is not endogenously expressed. The extent of current inhibition was not significantly different between naïve E52 cells and TRPV1-expressing E52 cells, suggesting no involvement of TRPV1. In contrast, TRPV1 activation is prerequisite for the inhibition of Ca(V)2.3 calcium channels by capsaicin. The results indicate that eugenol has mechanisms distinct from those of capsaicin for modulating Ca(V)2.3 channels. We suggest that inhibition of Ca(V)2.3 channels by eugenol might contribute to its analgesic effect.
Chung
G
G
Department of Physiology, School of Dentistry, Seoul National University, 28-2 Yeongeon-Dong, Chongno-Ku, Seoul, 110-749, Korea.
Rhee
J N
JN
Jung
S J
SJ
Kim
J S
JS
Oh
S B
SB
D000700:Analgesics / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D020908:Calcium Channels, R-Type / Q000187:drug effects*; D002211:Capsaicin / Q000494:pharmacology; D027682:Cation Transport Proteins / Q000187:drug effects*; D002460:Cell Line; D003764:Dental Materials / Q000494:pharmacology*; D005054:Eugenol / Q000494:pharmacology*; D006801:Humans; D018408:Patch-Clamp Techniques; D010957:Plasmids; D018689:Sensory System Agents / Q000494:pharmacology; D026941:Sodium Channel Blockers / Q000494:pharmacology; D015222:Sodium Channels / Q000187:drug effects; D050916:TRPV Cation Channels / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000235:genetics; D014162:Transfection
D000700:Analgesics; C423009:CACNA1E protein, human; D002121:Calcium Channel Blockers; D020908:Calcium Channels, R-Type; D027682:Cation Transport Proteins; D003764:Dental Materials; D018689:Sensory System Agents; D026941:Sodium Channel Blockers; D015222:Sodium Channels; D050916:TRPV Cation Channels; C494482:TRPV1 protein, human; D005054:Eugenol; D002211:Capsaicin