Detection of sodium channel toxins: directed cytotoxicity assays of purified ciguatoxins, brevetoxins, saxitoxins, and seafood extracts.
Neuroblastoma cells in culture were used to detect sodium channel-specific marine toxins based on an end-point determination of mitochondrial dehydrogenase activity. The assay responds in a dose-dependent manner to ciguatoxins, brevetoxins, and saxitoxins, and delineates the toxic activity as either sodium channel enhancing or sodium channel blocking. The assay responds rapidly to sodium channel activating toxins, allowing dose dependent detection in 4 to 6 h. Brevetoxins can be detected at 250 pg, and purified ciguatoxins are detected in the low picogram and subpicogram levels. The results obtained from cell bioassay of ciguatoxic finfish extracts correlates with those obtained from mouse bioassays. Sodium channel blocking toxins can also be detected with an approximate sensitivity of 20 pg in 24 to 48 h. This cell-based technique is simple, sensitive, demonstrates potential as an alternative to animal testing for sodium channel activating and blocking toxins, and can be automated.
Manger
R L
RL
U.S. Food and Drug Administration, Seafood Products Research Center, Bothell, WA 98041-3012, USA.
Leja
L S
LS
Lee
S Y
SY
Hungerford
J M
JM
Hokama
Y
Y
Dickey
R W
RW
Granade
H R
HR
Lewis
R
R
Yasumoto
T
T
Wekell
M M
MM
D000818:Animals; D001681:Biological Assay / Q000379:methods*; D003386:Brachyura; D002478:Cells, Cultured; D036841:Ciguatera Poisoning; D002922:Ciguatoxins / Q000302:isolation & purification*; D005399:Fishes; D008353:Mannitol / Q000494:pharmacology; D008387:Marine Toxins / Q000302:isolation & purification*; D051379:Mice; D009447:Neuroblastoma; D035964:Oxocins; D012530:Saxitoxin / Q000302:isolation & purification*; D017747:Seafood / Q000032:analysis*; D012680:Sensitivity and Specificity; D062687:Sodium Channel Agonists; D026941:Sodium Channel Blockers; D000095702:Polyether Toxins
D002922:Ciguatoxins; D008353:Mannitol; D008387:Marine Toxins; D035964:Oxocins; D012530:Saxitoxin; D062687:Sodium Channel Agonists; D026941:Sodium Channel Blockers; C053342:brevetoxin; D000095702:Polyether Toxins