pectenotoxin-6 and Diarrhea

Diarrhetic activity of pectenotoxin-6 (PTX6), a shellfish contaminant in Japanese scallops (Patinopecten yessoensis), was studied in vivo. Mice gavaged with 5mg/kg PTX6 did not show diarrhea or fluid secretion, and no prominent pathological changes were observed. There was no synergistic toxicity of PTX6 with okadaic acid (OA) or pectenotoxin-2 (PTX2) when toxins were given to mice by gavage. Synergistic activity of PTX6 with OA was also not confirmed under crude conditional simulation with oil. In contrast to the oral administration to mice, PTX6 at 500 microg/kg by i.p. was the lethal dose with bleeding in the liver, injuries at the gastric organs and the kidney. When rats were gavaged with PTX6 at a dose of 2 mg/kg, PTX6 did not have diarrhetic activity; however, the middle-lower small intestine (jejunum-ileum) was eroded at villi by edema. PTX6 is a potent toxin if administered by intraperitoneal injection to mice, or if administered orally to the rat. However, it is not clear if PTX6 passes through the intestinal barrier if given by the oral route.

Topics: Animals; Diarrhea; Dose-Response Relationship, Drug; Furans; Intestine, Small; Macrolides; Male; Marine Toxins; Mice; Mice, Inbred ICR; Molecular Structure; Okadaic Acid; Pectinidae; Pyrans; Rats; Rats, Wistar; Time Factors

Determination of diarrhetic shellfish-poisoning (DSP) toxins, okadaic acid (OA), dinophysistoxin-1 (DTX1) and pectenotoxin-6 (PTX6) was carried out by liquid chromatography (LC) followed by on-line atmospheric pressure electrospray ionization-mass spectrometric (ESI-MS) detection with a heated capillary interface. Mass spectra of authentic OA, DTXI and PTX6 standards exhibited abundant [M-H] at m/z 803, 817 and 887, respectively. Linearity of peak area obtained by selected-ion monitoring (SIM) for [M-H]- of each toxin was confirmed over a wide range of concentrations from 10 pg to 30 ng. LC-ESI-MS analysis of OA, DTX1 and PTX6 in scallops and mussels, collected at the same site (Mutsu Bay, Japan), was carried out. Scallops and mussels collected at the same site showed different toxin profiles. Although PTX6 was detected from scallops, it was not detected from mussels.

Topics: Animals; Bivalvia; Chromatography, Liquid; Diarrhea; Furans; Hydrolysis; Macrolides; Mass Spectrometry; Mollusk Venoms; Okadaic Acid; Pyrans; Reference Standards; Toxins, Biological