Kinetics of diarrhetic shellfish poisoning toxins, okadaic acid, dinophysistoxin-1, pectenotoxin-6 and yessotoxin in scallops Patinopecten yessoensis

Abstract

Four toxins, okadaic acid (OA), dinophysistoxin-1 (DTX1), pectenotoxin-6 (PTX6), and yessotoxin (YTX), all associated with diarrhetic shellfish poisoning (DSP), were administered via syringe to Scallops Patinopecten yessoensis and their distribution in the hepatopancreas, adductor muscle, and combined other tissues (mantle, gill, gonad) was analyzed by liquid chromatographymass spectrometry. Toxins exclusively remained in the hepatopancreas irrespective of the injection site, adductor muscle or hepatopancreas. When injected into hepatopancreas, OA, DTX1, and YTX were metabolized to 7-O -palmitoylOA, 7-O -palmitoylDTX1 and 45-hydroxyyessotoxin (45OH-YTX), respectively. Such metabolic changes were insignificant when toxins were injected into the adductor muscle. The residual ratio for each toxin in the hepatopancreas was less than 20%. Mortalities of scallops treated with PTX6 were lower than those treated with other toxins.

Comparison of cytotoxicity among pectenotoxin-2 and other oxidized pectenotoxins in a rat myoblast cell line (L6) and a human rhabdomyosarcoma cell line (RD)

“…Although the Japanese scallop Patinopecten yessoensis lacks the ability to detoxify PTX2 by hydrolyzing it to PTX2sa (Suzuki et al, 1998), PTX2 could be detoxified by an alternative conversion of PTX2 upon the oxidization of the 43-methyl group to the less cytotoxic PTX6 in this species. Our previous study found that the injection of P. yessoensis with PTX6 caused non-toxic symptoms (Suzuki et al, 2005). Thus, the present evaluation of the cytotoxicity of PTX6 is consistent with the results of our previous in vivo experiment on the scallops.…”

Quantification of lipophilic toxins associated with diarrhetic shellfish poisoning in Japanese bivalves by liquid chromatography-mass spectrometry and comparison with mouse bioassay

“…In Japan, the toxic dinoflagellate Dinophysis fortii , 11 which produces dinophysistoxin‐1 (DTX1) and pectenotoxin‐2 (PTX2), 12 and Protoceratium reticulatum , which produces yessotoxin (YTX), 13,14 are the most important species in the toxic phytoplankton monitoring program for early warning of DSP contamination of bivalves. Whereas DTX1, PTX2, and YTX are the parent toxins in Japanese bivalves, the other toxins are metabolites contained in bivalves 12,15–21 . In the present study, the LC–MS method reported in Quilliam et al .…”

“…Whereas DTX1, PTX2, and YTX are the parent toxins in Japanese bivalves, the other toxins are metabolites contained in bivalves. 12,[15][16][17][18][19][20][21] In the present study, the LC-MS method reported in Quilliam et al was modified to quantify major lipophilic toxins associated with DSP in Japanese bivalves. 22 To facilitate this approach to routine monitoring of toxins in bivalves, a divert valve was installed to the LC-MS system to protect the ion source and MS detector from biological matrices in a sequence of analyses of crude 90% methanol sample extracts.…”

Okadaic Acid Meet and Greet: An Insight into Detection Methods, Response Strategies and Genotoxic Effects in Marine Invertebrates

“…However, what seems now clear is that transformation processes as hydrolysis (during digestion) and, most importantly, acylation are decisive for the metabolism of OA, producing free toxin and esters. Indeed, the rapid bioconversion of OA to 7- O -acyl derivates can be taken as a defense mechanism against this biotoxin, though the hydrophobic nature of the esters may slow their elimination from tissues via body fluid [45]. Although a role in OA acylation was initially ascribed to bacteria present in the bivalve gut [46], it was later demonstrated that in mussels the OA is primarily transformed in the endoplasmic reticulum [47].…”