Quantitation of paralytic shellfish toxins using mouse brain synaptoneurosomes.
A membrane potential assay based on synaptoneurosomes prepared from mouse brain was evaluated further for its utility in estimating saxitoxin and related bioactives. Saxitoxin concentrations quantitated in mussel extracts by the synaptoneurosomal technique correlated well with spiked concentrations in these samples (r2 = 0.995; slope=1.048). Other experiments found that the synaptoneurosomal assay can detect saxitoxin-like bioactives in zooplankton samples and the concentrations measured were consistent with preliminary estimations of saxitoxin equivalents using the [3H] saxitoxin receptor binding technique. Veratrine, a mixture of alkaloids that activate sodium channels, had similar potential as a substitute for veratridine in the synaptoneurosomal assay. The results provide additional evidence that the mouse brain synaptoneurosomal membrane potential assay has excellent capability for quantitation of saxitoxin-like activity in shellfish tissues and may also be applied to zooplankton samples.
David
Laurence S
LS
Department of Biological Sciences, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada V5A 1S6.
Nicholson
Russell A
RA
D000818:Animals; D049872:Bivalvia / Q000737:chemistry*; D001921:Brain / Q000502:physiology*; D005453:Fluorescence; D008564:Membrane Potentials / Q000187:drug effects*; D051379:Mice; D008815:Mice, Inbred Strains / Q000502:physiology*; D012235:Rhodamines; D012530:Saxitoxin / Q000032:analysis* / Q000494:pharmacology; D013574:Synaptosomes / Q000187:drug effects* / Q000502:physiology; D014701:Veratridine; D014702:Veratrine; D015048:Zooplankton / Q000737:chemistry
D012235:Rhodamines; C026188:rhodamine 6G; D012530:Saxitoxin; D014701:Veratridine; D014702:Veratrine