Shellfish poisoning

Other Lethal Agents. There are a number of substances, many found in nature, which are known to be more toxic than nerve agents (6). None has been weaponized. Examples of these toxic natural products include shellfish poison, isolated from toxic clams puffer fish poison, isolated from the viscera of the puffer fish the active principle of curare "heart poisons" of the digitaUs type the active principle of the sea cucumber active principles of snake venom and the protein ricin, obtained from castor beans (See Castor oil). 

Figure 5.59 Molecular structures of the diarrhetic shellfish poisons (a) pectenotoxin-6 (PTX6) (b) okadaic acid (OA) (c) dinophysistoxin-1 (DTXl) (d) yessotoxin (YTX). Reprinted from J. Chromatogr., A, 943, Matrix effect and correction by standard addition in quantitative liquid chromatographic-mass spectrometric analysis of diarrhetic shellfish poisoning toxins , Ito, S. and Tsukada, K., 39-46, Copyright (2002), with permission from Elsevier Science.

High-Performance Liquid Chromatographic Method Applied to Parafytic Shellfish Poisoning Research... 

The use of high performance liquid chromatography (HPLC) for the study of paralytic shellfish poisoning (PSP) has facilitated a greater understanding of the biochemistry and chemistry of the toxins involved. HPLC enables the determination of the type and quantity of the PSP toxins present in biological samples. An overview of the HPLC method is presented that outlines the conditions for both separation and detection of the PSP toxins. Examples of the use of the HPLC method in toxin research are reviewed, including its use in the determination of the enzymatic conversion of the toxins and studies on the movement of the toxins up the marine food chain. 

Acute poisoning of humans by freshwater cyanobacteria as occurs with paralytic shellfish poisoning, while reported, has never been confirmed. Humans are probably just as susceptible as pets, livestock, or wildlife but people naturally avoid contact with heavy waterblooms of cyanobacteria. In addition, there are no known vectors, like shellfish, to concentrate toxins from cyanobacteria into the human food chain. Susceptibility of humans to cyanobacteria toxins is supported mostly by indirect evidence. In many of these cases, however, if a more thorough epidemiological study had been possible these cases probably would have shown direct evidence for toxicity. 

Three classes of polyethers, okadaic acid derivatives, pectenotoxins, and yessotoxin were isolated from bivalves in connection with diarrhetic shellfish poisoning. The etiology of the toxins, toxicological properties, and determination methods are described. 

Diarrhetic shellfish poisoning is an illness caused by polyether toxins produced by dinoflagellates and accumulated in shellfish (31). Patients suffer from diarrhea, nausea, and stomach pain but recover within three days without serious aftereffects. Despite the relatively mild symptoms, careful attention should be paid to the... 

This chapter deals with single crystal x-ray diffraction as a tool to study marine natural product structures. A brief introduction to the technique is given, and the structure determination of PbTX-1 (brevetoxin A), the most potent of the neurotoxic shellfish poisons produced by Ptychodiscus brevis in the Gulf of Mexico, is presented as an example. The absolute configuration of the brevetoxins is established via the single crystal x-ray diffraction analysis of a chiral 1,2-dioxolane derivative of PbTX-2 (brevetoxin B). 

The toxicological consequences of P. brevis red tides are mass mortality of fishes exposed to the red tide toxic shellfish which, if consumed, result in human neurotoxic shellfish poisoning and an irritating aerosol which results from contact with P. brevis cell particles entrapped in seaspray. In all cases, the threshhold levels for intoxication are in the picomolar to nanomolar concentration ranges, implying a specific locus or loci of action for brevetoxins (reviewed in 6). 

In addition to okadaic acid, dinophysistoxin-1 (i.e., 35-methylokadaic acid), 7-0-palmitoyl-okadaic acid, and pectenotoxin 2 are reported to be diarrhetic toxins from shellfish 34). Application of 1 xg of dinophysistoxin-1 to mouse ear caused as strong irritation as the same dose of okadaic acid. Interestingly, the potencies of these compounds in the irritant test on mouse ear correlated well with their potencies as diarrhetic shellfish poisons. Dinophysistoxin-1 induced ODC activity as strongly as okadaic acid. Recently, we found that dinophysistoxin-1 is also a new non-TPA type tumor promoter with as high activity as okadaic acid 35). 

Second, there has been another severe outbreak of paralytic shellfish poisoning along the Pacific coast of Central America, with veiy high levels of shellHsh toxicity detected in Guatemala. There have, however, been no deaths and very few illnesses reported there, due to a timely response based on information gained from detailed investigations of the first outbreak. This time they were ready. 

DMS Dimethylsulfide DMSP Dimethylsulfoniopropionate DSP Diarrhetic shellfish poisoning PSP Paralytic shellfish poisoning PUFA Polyunsaturated fatty acid... 

Some dinoflagellates of the genus Alexandrium produce neurotoxic compounds known as paralytic shellfish poisoning (PSP) toxins. Because these toxins can contaminate filter-feeding shellfish they may threaten public health and create economic problems for fisheries. PSP-toxins include at least a dozen saxitoxins, neosaxitoxins, and gonyautoxins (Scheme 1). 

Rapid-acting paralytic neurotoxins that blocks transient sodium channels and inhibits depolarization of nerve cells. They are some of the causative agents of paralytic shellfish poisoning (PSP). They are obtained from dinoflagellates (Gonyaulax spp., Alexandrium spp.) and cyanobacteria (Anabaena circinalis). 

---