Inhibition of Voltage-Gated Potassium Currents by Gambierol in Mouse Taste Cells

Ciguatera is a food poisoning caused by toxins of Gambierdiscus toxicus, a marine dinoflagellate. The neurological features of this intoxication include sensory abnormalities, such as paraesthesia, heightened nociperception, and also taste alterations. Here, we have evaluated the effect of gambierol, one of the possible ciguatera toxins, on the voltage-gated ion currents in taste cells. Taste cells are excitable cells endowed with voltage-gated Na+, K+, and Cl currents (INa, IK, and ICl, respectively). By applying the patch-clamp technique to single cells in isolated taste buds obtained from the mouse vallate papilla, we have recorded such currents and determined the effect of bath-applied gambierol. We found that this toxin markedly inhibited IK in the nanomolar range (IC50 of 1.8 nM), whereas it showed no significant effect on INa or ICl even at high concentration (1 mM). The block of IK was irreversible even after a 50-min wash. In addition to affecting th