IC50: voltage-gated Na ⁺ channel

Brevetoxin-3 (PbTx-3)(30-500 nM) produces a shift in activation to more negative membrane potentials whereby single-channel activity is observed under steady-state conditions (maintained depolarization at -50 mV).

Brevetoxin-3 (PbTx-3)(intratracheal instillation; 2.8 μg/kg; gestational days 15-18)?radioactivity is detected in placentas and fetuses within 0.5 hours. Concentrations of brevetoxin equivalents in fetuses are approximately 0.3 ng/g throughout the 48-h post-dosing, resulting in a calculated dose to fetuses of 19 ng/gh. Following brevetoxin infusion, concentration of brevetoxin equivalents in fetuses is 0.1 ng/g, lower than that present in most maternal tissues. .