Reptile venom is complex mixtures of biological compounds that have potent effects on their targets. The venoms of snakes from the families Elapidae (reclassified as a subfamily under Viperidae) and Crotalidae (reclassified as a viperid subfamily) are most well-studied, but many potential drugs are also derived from other lizard venoms.
크레스티드게코Why Snakes Preserve Their Venom
The venom of snakes, fishes and amphibians, insects and spiders, sea anemones and jellyfish is made up of chemical compounds that attack and disable ion channels and G-protein-coupled membrane receptors. The poisons work through spurs, stingers or fangs, and are used for killing and digesting prey or self-defense.
A venomous snake houses its venom in glands near the mouth, and can deliver it in a quick bite. While it doesn’t always kill its prey, the venom does slow its breathing and causes paralysis. The most common reason a snake bites, though, is for food.
Unlike boas, which constrict their prey, venomous snakes inject their venom directly into their prey using the fangs in the center of their mouths. They can also use the venom to ward off predators, but research shows that this rarely happens. In fact, few bites result in pain that is debilitating within five minutes, and most snakes don’t even sting their prey at all.
That’s because most snake venom is protein-based, and proteins are incredibly fragile in the presence of acid. The stomach acids in a snake’s body break down the proteins in the venom so that it can’t enter the bloodstream and cause any real damage. It’s the same reason why you don’t get sick from eating meat: the proteins are broken down by the stomach acids in your body so that they can’t affect you.
Venom is a Natural Gift
Snakes that are venomous, such as vipers and elapids (cobras, coral snakes, mambas and sea snakes), manufacture their own poison internally. They have glands in their head that produce highly toxic saliva which is then injected through specialized fangs during a strike, or spitted by some species. The venom contains zootoxins that facilitate immobilization and digestion of prey, as well as defense against threats.
Venom is a complex mixture of proteins and other biological compounds, some of which act on specific cell types, causing cellular damage or even death. The different kinds of venom vary depending on the species of snake. Some are neurotoxic, affecting the nervous system; others are hemotoxic, destroying blood cells and causing extensive bleeding. Hemotoxic venoms are produced by rattlesnakes and other members of the viperidae family, while neurotoxic venom is found in cobras and coral snakes.
Snakes conserve their venom as a natural weapon, which they reserve to hunt and subdue prey. They do not use it unnecessarily, however, because injecting it drains a great deal of energy from their body, so they must be careful how they use it. Scientists also preserve snake venom as a source of medical science, since the toxins can be used to make drugs that treat diseases such as cancer, high blood pressure, arthritis and other conditions.
Venom is a Weapon
Venom is a deadly weapon, and just a minuscule amount of it can paralyze a rodent. It is a powerful, multi-targeted cocktail of chemicals that attacks multiple bodily systems at once. Its primary function is to subdue and kill prey, but it also helps snakes defend themselves against predators.
Every year, venomous snakes like cobras and kraits kill around 100,000 people and maim twice as many, mostly in the developing world. The venoms of these snakes and others kill by poisoning blood cells and causing severe bleeding at the bite site and all body openings, including the nose and mouth. Some venoms have neurotoxins that cause paralysis and respiratory and heart failure, while others, such as that of the boomslang (Dispholidus typus) and the twig snake (Thelotornis spp), have hemorrhagic effects and thinning the blood, which causes exsanguination and may be fatal if untreated.
Scientists have figured out how to create antivenoms that block the action of a particular toxin, but it is a complicated process, and there are many different toxins. It’s also impossible to formulate cures for all species of venomous snake, and the complexity of the chemical composition of each venom is part of the reason why a universal cure remains a scientific pipe-dream.
Venom is a Threat
Venom has helped snakes survive for millions of years and further their species, but it can also be used to kill humans. It takes a lot of energy to produce and store, so snakes will only use it on prey that they feel threatens them or their young. The venom they preserve is their greatest weapon, and a precious gift they will not waste.
Venom is a complex brew of many compounds and is divided into two basic types: neurotoxins and haemotoxins. Neurotoxins disable the nervous system of their prey and cause it to stop working, suffocating them. Haemotoxins destroy blood cells and break down the clotting compounds in their victims, leading to uncontrolled bleeding. Snake venom contains more than 100 different toxins, and a cocktail of them is often deadly.
Snakes have evolved to have a wide range of venoms, and they are able to adapt it to suit their needs. Some venoms have more toxicity than others, and some have more potent neurotoxins or haemotoxins. Depending on their evolutionary history and the needs of their prey, snakes can also add different enzymes to their venom to improve its effectiveness.
Scientists have been able to isolate and focus on specific components of snake venom, and this has led to the development of anti-venoms that are able to counteract the effects of some snake toxins. Other venom components have been used to develop drugs that treat everything from diabetes to heart attacks.