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The polyether lipid-soluble toxins isolated from the marine dinoflagellate Ptychodiscus brevis (formerly Gymnodinium breve) have been determined to bind to a unique site associated with rat brain synaptosomes. Using [3H]brevetoxin PbTx-3 as a specific probe, binding was determined at 4 degrees in rat brain synaptosomes using a rapid centrifugation(More)
To identify the binding domain for brevetoxins, a family of lipid-soluble neurotoxins acting at Na+ channel receptor site 5, purified and reconstituted rat brain Na+ channels were photolabeled with p-azidobenzoyl tritium-labeled brevetoxin, and the labeled peptides were identified. A radiolabeled band with an apparent molecular mass of 250 kDa corresponding(More)
The marine toxin gambierol, a polyether ladder toxin derived from the marine dinoflagellate Gambierdiscus toxicus, was evaluated for interaction with voltage-gated sodium channels (VGSCs) in cerebellar granule neuron (CGN) cultures. At concentrations ranging from 10 nM to 10 microM, gambierol alone had no effect on the intracellular Ca2+ concentration(More)
Florida red tides are a natural phenomenon caused by dense aggregations of single cell or several species of unicellular organisms. Patches of discolored water, dead or dying fish, and respiratory irritants in the air often characterize these algal blooms. In humans, two distinct clinical entities, depending on the route of exposure, are associated with(More)
In 1996, at least 149 manatees (Trichechus manatus latirostris) died in an unprecedented epizootic along the southwest coast of Florida. At about the same time, a bloom of the brevetoxin-producing dinoflagellates, Gymnodinium breve, was present in the same area. Grossly, severe nasopharyngeal, pulmonary, hepatic, renal, and cerebral congestion was present(More)
Potent marine neurotoxins known as brevetoxins are produced by the 'red tide' dinoflagellate Karenia brevis. They kill large numbers of fish and cause illness in humans who ingest toxic filter-feeding shellfish or inhale toxic aerosols. The toxins are also suspected of having been involved in events in which many manatees and dolphins died, but this has(More)
  • D G Baden
  • 1989
Brevetoxins are lipid-soluble polyether marine toxins of unique structure and pharmacological function. Toxins are active in vivo in the nanomolar to picomolar concentration range and in vitro in isolated neuromuscular or giant axon preparations and in single-cell or subcellular model systems. Their effect is excitatory, mediated by the enhancement of(More)
Symptoms consistent with inhalation toxicity have long been associated with Florida red tides, and various causal agents have been proposed. Research since 1981 has centered on a group of naturally occurring trans-fused cyclic polyether compounds called brevetoxins that are produced by a marine dinoflagellate known as Karenia brevis. Numerous individual(More)
Brevetoxin-3 (PbTx-3), produced by marine dinoflagellates (Ptychodiscus brevis), is a lipophilic 11-ring polyether molecule that binds with high affinity to site 5 of the voltage-sensitive sodium (Na+) channel. The effects of PbTx-3 and its derivatives were studied in cell-attached membrane patches on neurons dissociated from neonatal rat nodose ganglia by(More)
1. Florida red tides produce profound neurotoxicity that is evidenced by massive fish kills, neurotoxic shellfish poisoning, and respiratory distress. Red tides vary in potency, potency that is not totally governed by toxin concentration. The purpose of the study was to understand the variable potency of red tides by evaluating the potential for other(More)