The toxinology of sea snake venoms

Sea snakes are widely distributed in the warmer regions of the Indian and Pacific Oceans. Their venoms are much higher toxic than those of terrestrial snakes. The main lethal factor is postsynaptic neurotoxins which are small basic proteins consisting of 60 - 74 amino acid residues. They bind almost irreversibly to the nicotinic acetylcholine receptor and block the neuromuscular junction. Besides neurotoxins, myotoxic phospholipases A(2) are present in the venoms of some species of sea snakes. In the sea snake envenomation, the causes of death are respiratory failure which occures when the respiratory muscles are affected, or the acute renal failure associated with myoglobinuria caused by myotoxic effects.