Hemotoxic venoms

Hemotoxic venoms of rattlesnakes and cottonmouths contain as their principal toxin phosphodiesterase, an enzyme that catalyzes hydrolysis ofphosphodiester bonds in ATP and other substrates. 

Snake venoms are complex mixtures of several different components or fractions that can vary considerably within Crotalinae members. A complete review of venom components is beyond the scope of this review. Depending on the content of the venom, multiple organ systems may be affected. Historically, Crotalinae venom was classified as neurotoxic, hemotoxic, cardiotoxic, or myotoxic, depending on the species of snake involved in the envenomation. This oversimplifies the complex nature of Crotalinae venom. Clinically, a patient may develop such multisystem disorders as platelet destruction, internal bleeding, hypotension, paresthesias, and rhabdomyolysis. 

I. Mechanism of toxicity. Snake venoms are complex mixtures of 50 or more components that function to immobilize, kill, and predigest prey. In human victims, these substances produce local digestive effects on tissues as well as hemotoxic, neurotoxic, and other systemic effects. The relative predominance of digestive, hemotoxic, or neurotoxic venom components depends on the species of the snake and geographic variables. 

In nature, the art of chemical warfare may have reached its zenith with the innovation of venomous animals, those that not only contain poisonous toxins but also have the anatomical apparatus to inject those toxins directly into other animals. Venoms come in four different types cytotoxic, causing cell death proteolytic, dismantling the molecular structure around the area of the injection hemotoxic, causing failure within the cardiovascular system or neurotoxic, acting on the nervous system and the brain. 

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