pectenotoxin-1 and dinophysistoxin-1

Diarrhetic Shellfish Poisoning (DSP) is a specific type of food poisoning, characterized by severe gastrointestinal illness due to the ingestion of filter feeding bivalves contaminated with a specific suite of toxins. It is known that the problem is worldwide and three chemically different groups of toxins have been historically associated with DSP syndrome: okadaic acid (OA) and dinophysistoxins (DTXs), pectenotoxins (PTXs) and yessotoxins (YTXs). PTXs and YTXs have been considered as DSP toxins because they can be detected with the bioassays used for the toxins of the okadaic acid group, but diarrhegenic effects have only been proven for OA and DTXs. Whereas, some PTXs causes liver necrosis and YTXs damages cardiac muscle after intraperitoneal injection into mice. On the other hand, azaspiracids (AZAs) have never been included in the DSP group, but they cause diarrhoea in humans. This review summarizes the origin, characterization, structure, activity, mechanism of action, clinical symptoms, method for analysis, potential risk, regulation and perspectives of DSP and associated toxins produced by marine dinoflagellates.

Topics: Animals; Dinoflagellida; Humans; Liver; Macrolides; Mice; Molecular Structure; Mollusk Venoms; Myocardium; Necrosis; Okadaic Acid; Oxocins; Pyrans; Rats; Shellfish; Shellfish Poisoning; Toxicity Tests

Mussels exposed to dinoflagellates may represent a human health risk due to accumulation of a variety of algal toxins. In several parts of the world, algal toxins leading to diarrhea (diarrhetic shellfish poisons, DSP) are found in mussels for extended periods of the year. Routine monitoring of these toxins involves ip injections in mice. Chemical analytical methods have been developed for only some of the toxins in question, namely, those giving diarrhea. Other toxins in the DSP complex are not easily detected by analytical methods. In this report we show that freshly prepared hepatocytes from rats are a convenient means to differentiate between the toxins that give diarrhea and those that do not. Consequently, hepatocytes can be useful in both screening and as a tool in the process of developing analytical methods. Freshly prepared hepatocytes might be useful in combination either with the mouse bioassay or with chemical analytical methods.

Topics: Animals; Bacterial Toxins; Bivalvia; Cells, Cultured; Cyanobacteria Toxins; Diarrhea; Dose-Response Relationship, Drug; Ethers, Cyclic; L-Lactate Dehydrogenase; Liver; Macrolides; Male; Marine Toxins; Microcystins; Microscopy, Electron, Scanning; Mollusk Venoms; Okadaic Acid; Oxocins; Pyrans; Rats; Shellfish

Sequential ultrastructural changes were studied in mouse digestive organs after i.p. injections of dinophysistoxin-1 and pectenotoxin-1, causative agents of diarrhetic shellfish poisoning. Dinophysistoxin-1, a diarrheagenic substance, produced severe mucosal injuries in the small intestine within 1 hr after the administration of the toxin. The injuries were divided into 3 consecutive stages: extravasation of villi vessels, degeneration of absorptive epithelium and desquamation of the degenerated epithelium from the lamina propria. In contrast to dinophysistoxin-1, pectenotoxin-1, a non-diarrheagenic toxin from diarrhetic shellfish poisoning causative mussels, resulted in no abnormalities in the small intestine, but did cause characteristic liver injuries. Within 1 hr after the injection of pectenotoxin-1 numerous non-fatty vacuoles appeared in the hepatocytes around the periportal regions of the hepatic lobules. Electron microscopic observations with colloidal iron demonstrated that these vacuoles originated from invaginated plasma membranes of the hepatocytes.

Topics: Animals; Animals, Suckling; Duodenum; Female; Liver; Macrolides; Male; Marine Toxins; Mice; Mice, Inbred BALB C; Microscopy, Electron; Okadaic Acid; Pyrans