A simple and reliable method using liquid chromatography/electrospray ionization-mass spectrometry (LC/ESI-MS) for the analysis of tetrodotoxin in puffer-fish was developed. Tetrodotoxin in puffer-fish was extracted with 0.1% acetic acid by heating in a boiling water bath, and the extracts were cleaned up on a Bond Elut C18 (500 mg) cartridge. The LC separation was performed on a TSK-gel ODS 80...

The efflux of 22Na from vesicles formed by axolemma fragments isolated from lobster nerves was studied in the presence and in the absence of drugs having well-known action on the sodium channels. The vesicles were equilibrated 12-14 h at 4 degrees C with 22Na in lobster solution containing 1 mM ouabain. Afterwards the suspension was divided: one portion was used as control and the others were t...

NARAHASHI, TOSHIO, TAKEHIKO DEGUCHI, NORIMOTO URAKAWA AND YOSHIO OHKUBO. Stabilisation and rectijication of muscle jber membrane by tetrodotoxin. Am. J. Physiol. I $3 (5) : 934-938. 1g6o.-The mode of action of tetrodotoxin on the frog muscle fiber membrane has been analyzed with the aid of intracellular microelectrodes. Tetrodotoxin of I oH7 concentration made the applied cathodal current ineff...

BACKGROUND AND PURPOSE Studies examining the role of tetrodotoxin-sensitive ion channels in hypoxic-ischemic neuronal damage have concluded that sodium influx is an important initiating event. We examined the neuroprotectant effect of tetrodotoxin on both cultured cerebellar neurons and on CA1 hippocampal neurons of gerbils exposed to brain ischemia. METHODS We studied neuroprotective mechani...

Previous studies suggested that tetrodotoxin, a poison from the puffer fish, blocks conduction of nerve and muscle through its rather selective inhibition of the sodium-carrying mechanism. In order to verify this hypothesis, observations have been made of sodium and potassium currents in the lobster giant axons treated with tetrodotoxin by means of the sucrose-gap voltage-clamp technique. Tetro...

Low levels of saxitoxins and tetrodotoxin were found in the viscera of adult chum salmon Oncorhynchus keta returning to spawn. The nucleic magnetic resonance and mass spectrum analyses as well as several kinds of chromatographies clearly showed that the purified toxins were saxitoxin and neosaxitoxin. Tetrodotoxin, which was detected by high performance l~qu id chromatography analysis, could no...

BACKGROUND Local anesthetics exert antiinflammatory actions. To elucidate potential mechanisms, the authors examined effects of bupivacaine or tetrodotoxin, administered to rats by ipsilateral or contralateral sciatic blockade or systemically, on carrageenan-induced hind paw hyperalgesia, edema, and stimulated cytokine production in circulating blood cells. METHODS Twelve groups of rats (n = ...

It has been accepted that puffer fish accumulates tetrodotoxin through the food chain. This indicates that tetrodotoxin in puffer fish is exogenous. The present study, however, describes an endogenous origin of tetrodotoxin in puffer fish. For this purpose, the ovulated oocytes from puffer fish Fugu niphobles were artificially fertilized and cultivated. The toxin levels of embryos increased gra...

1. Tetrodotoxin, at concentrations at which it abolishes generation of action potentials in the nervous system, enhances by about 300% the rate of anaerobic glycolysis of brain-cortex slices from adult rats, or from adult and infant guinea pigs. This occurs to a greater extent in Ca(2+)-deficient incubation media than in Ca(2+)-rich media. Tetrodotoxin has no accelerative effect on cerebral aer...