The batrachotoxin increases the permeability of the outer membrane of nerve and muscle cells to sodium ions. Thus it stops these channels within muscle fibres from closing normally, allowing a big inflow of sodium ions into the cell. This causes an irreversible electrical depolarisation, blocking the nerve signals that would normally cause the muscle to relax, the muscle remaining contracted. Certain cells within the heart are very sensitive to this, resulting in heart arrythmias, fibrillation and ultimately cardiac failure.
Batrachotoxin is among the most toxic substances known, more toxic than curare or the tetrodotoxin, used by the puffer fish (itself over 1000 times more poisonous than cyanide). Other frogs use different poisons, but none as toxic as batrachotoxin. Currently no effective antidote exists for the treatment of batrachotoxin poisoning. However, the cell membrane depolarization can be prevented or reversed by either tetrodotoxin (from puffer fish), which is a noncompetitive inhibitor, or saxitoxin ("red tide"). These both have effects antagonistic to those of batrachotoxin on sodium flux. Certain anesthetics may act as antagonists to the action of this alkaloid poison, while other local anesthetics block its action altogether by acting as competitive antagonists.
Scientists are using this molecule to study the way in which nervous impulses are transmitted in animals. They are being studied for possible applications in areas like heart drugs and anaesthetics.
2007-02-17 01:17:41
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answer #1
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answered by Jesus is my Savior 7
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