Crotoxin is the principle neurotoxin found in the venom of rattlesnakes (Crotalus species), and is similar to the neurotoxins found in other members of the Viperidae (venomous snake) family. It comprises over 50% of the rattlesnake’s venom proteins. According to the article, “Crotoxin, the major toxin from the rattlesnake Crotalus durissus terrificus,” crotoxin is composed of two subunits, a toxic phospholipase and a nontoxic acidic protein. Neither of these is dangerous unto itself, but the combination is deadly.
How Snake Venom Works
Most snakes are constrictors, meaning they capture their food and in effect, squeeze it to death, then swallow it whole. It may take several days, or even a week, to digest prey, depending on the size of the snake and the prey. Constrictors’ systems are equipped with powerful acids that can break down bone and hair and every other part of the prey.
Venomous snakes lack this ability in their digestive systems and thus, the digestive process must begin outside of the body through envenomation. As soon as the prey is injected with venom, it starts to die. Body processes are slowly shut down, and essentially, the prey begins to decompose before it has even died.
The venom acts on the nervous system, impairing antibody production and ensuring the breakdown of cells. Inflammation of the bitten area occurs. Respiratory and circulatory disturbances are induced. Muscles become paralyzed. Blood will not coagulate. If left untreated in human snakebite victims, death through respiratory failure will occur.
The Antivenin “CICS”
All venomous snakes possess a type of protein in their blood that helps them to resist their own venom. Rattlesnakes have a protein in their plasma called "CICS" (crotoxin inhibitor from Crotalus serum), which neutralizes the toxicity of their venom and inhibits enzymatic activity.
Scientists can now isolate and purify CICS. Studies of rabbits, dogs, and other animals similar to humans in body structure and venom reactions that have been injected with CICS have shown that it can provide a powerful antivenin. This antivenin is effective not only on victims bitten by Crotalus species but for all snakes in the Viperidae family, which are found on five continents.
Sources
De Lima, M.E.; C.R. Diniz, L.S. Kattah, M.M. 2000. Crotoxin, the major toxin from the rattlesnake Crotalus durissus terrificus, inhibits 3H-choline uptake in guinea pig ileum. Brazilian Journal of Medical and Biological Research. 33: 1093-1097.
Klauber, L.M. Rattlesnakes: Their Habitats, Life Histories, and Influence on Mankind. Second Edition. University of California Press: Berkeley, 1997.
Warrell, D.A. Snakebites in Central and South America: Epidemiology, Clinical Features, and Clinical Management in Campbell, J.A.; W.W. Lamar. The Venomous Reptiles of the Western Hemisphere. Comstock Publishing Associates: Ithaca and London, 2004.
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