Brevetoxin 3 (Synonyms: PbTx-3, T-17 Toxin)

Brevetoxin 3 is a neurotoxin produced by the dinoflagellate K. brevis.^1,2 It binds to site 5 of voltage-gated sodium channels (Na_vs), prolonging the mean open time and inhibiting inactivation of these channels.² Brevetoxin 3 induces the release of lactate dehydrogenase (LDH), L-glutamate, and L-aspartate from primary rat cerebellar granule neurons (CGNs; EC₅₀s = 30.9, 45.3, and 50.2 nM, respectively).³ It induces convulsions in, and is lethal to (LD₅₀ = 4 ng/egg), Japanese rice fish embryos.¹ Brevetoxin 3 has been found in water samples collected during red tide blooms.⁴

1.Colman, J.R., and Ramsdell, J.S.The type B brevetoxin (PbTx-3) adversely affects development, cardiovascular function, and survival in Medaka (Oryzias latipes) embryosEnviron. Health Perspect.111(16)1920-1925(2003) 2.Jeglitsch, G., Rein, K.S., Baden, D.G., et al.Brevetoxin-3 (PbTx-3) and its derivatives modulate single tetrodotoxin-sensitive sodium channels in rat sensory neuronsJ. Pharmacol. Exp. Ther.284(2)516-525(1997) 3.Berman, F.W., and Murray, T.F.Brevetoxins cause acute excitotoxicity in primary cultures of rat cerebellar granule neuronsJ. Pharmacol. Exp. Ther.290(1)439-444(1999) 4.Pierce, R.H., and Henry, M.S.Harmful algal toxins of the Florida red tide (Karenia brevis): Natural chemical stressors in South Florida coastal ecosystemsEcotoxicology17(7)623-631(2008)