Solid-phase radioreceptor assay for paralytic shellfish toxins.
Sodium channels obtained from rat brain membrane preparations were coated onto microtiter plates and used to develop a direct solid-phase binding assay. The tritiated sodium channel blocker saxitoxin ([3H]-saxitoxin; STX) was used to detect toxins in paralytic shellfish poisoning (PSP) by measuring the competitive displacement of other toxins. With this assay the amount of STX and tetrodotoxin needed to displace 50% of bound [3H]STX was 1.7 and 1.76 ng/ml for buffer samples, respectively. In the direct solid-phase binding assays, the PSP toxins were effectively bound to the rat brain membranes. The IC50 of this assay for different PSP toxin solutions obtained from mussels contaminated in red tides ranged from 0.03 to 0.30 ng/ml. Therefore, this assay represents a potentially useful method for the detection of toxin-contaminated mussels.
Departmento de Fisiologiá, Facultad de Veterinaria, Lugo, Spain.
M R
MR
Vieytes
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Cabado
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A
Alfonso
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MC
Louzao
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AM
Botana
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Botana
D000818:Animals; D001667:Binding, Competitive; D049872:Bivalvia / Q000737:chemistry*; D005260:Female; D066298:In Vitro Techniques; D008387:Marine Toxins / Q000032:analysis*; D009498:Neurotoxins / Q000032:analysis*; D010243:Paralysis / Q000139:chemically induced; D011869:Radioligand Assay / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012530:Saxitoxin / Q000378:metabolism; D012680:Sensitivity and Specificity; D015222:Sodium Channels / Q000187:drug effects* / Q000378:metabolism
D008387:Marine Toxins; D009498:Neurotoxins; D015222:Sodium Channels; D012530:Saxitoxin