Effect of ciguatoxin 3C on voltage-gated Na+ and K+ currents in mouse taste cells.
The marine dinoflagellate Gambierdiscus toxicus produces highly lipophilic, polycyclic ether toxins that cause a seafood poisoning called ciguatera. Ciguatoxins (CTXs) and gambierol represent the two major causative agents of ciguatera intoxication, which include taste alterations (dysgeusiae). However, information on the mode of action of ciguatera toxins in taste cells is scarce. Here, we have studied the effect of synthetic CTX3C (a CTX congener) on mouse taste cells. By using the patch-clamp technique to monitor membrane ion currents, we found that CTX3C markedly affected the operation of voltage-gated Na(+) channels but was ineffective on voltage-gated K(+) channels. This result was the exact opposite of what we obtained earlier with gambierol, which inhibits K(+) channels but not Na(+) channels. Thus, CTXs and gambierol affect with high potency the operation of separate classes of voltage-gated ion channels in taste cells. Our data suggest that taste disturbances reported in ciguatera poisoning might be due to the ability of ciguatera toxins to interfere with ion channels in taste buds.
Ghiaroni
Valeria
V
Dipartimento di Scienze Biomediche, Università di Modena e Reggio Emilia, Via Campi 287, 41100 Modena, Italy.
Fuwa
Haruhiko
H
Inoue
Masayuki
M
Sasaki
Makoto
M
Miyazaki
Keisuke
K
Hirama
Masahiro
M
Yasumoto
Takeshi
T
Rossini
Gian Paolo
GP
Scalera
Giuseppe
G
Bigiani
Albertino
A
D000818:Animals; D002922:Ciguatoxins / Q000737:chemistry / Q000494:pharmacology*; D004988:Ethers, Cyclic / Q000737:chemistry / Q000494:pharmacology; D015640:Ion Channel Gating / Q000187:drug effects*; D051379:Mice; D009924:Organ Culture Techniques; D018408:Patch-Clamp Techniques; D011083:Polycyclic Compounds / Q000737:chemistry / Q000494:pharmacology; D024642:Potassium Channels, Voltage-Gated / Q000187:drug effects; D015222:Sodium Channels / Q000187:drug effects*; D013649:Taste / Q000187:drug effects / Q000502:physiology; D013650:Taste Buds / Q000166:cytology* / Q000187:drug effects*; D035964:Oxocins
D002922:Ciguatoxins; D004988:Ethers, Cyclic; D011083:Polycyclic Compounds; D024642:Potassium Channels, Voltage-Gated; D015222:Sodium Channels; C466858:ciguatoxin 3C; C435770:gambierol; D035964:Oxocins