Hemotoxin

Haemotoxins,hemotoxinsorhematotoxinsaretoxinsthat destroyred blood cells,disruptbloodclotting,and/or causeorgandegeneration and generalizedtissuedamage. The termhaemotoxinis to some degree amisnomersince toxins that damage the blood also damage other tissues. Injury from a haemotoxic agent is often very painful and can cause permanent damage and in severe cases death. Loss of an affected limb is possible even with prompt treatment.

Haemotoxins are frequently employed byvenomousanimals, including snakes (vipersandpit vipers) and spiders (brown recluse). Animal venoms containenzymesand otherproteinsthat are haemotoxic orneurotoxicor occasionally both (as in theMojave rattlesnake,theJapanese mamushi,and similar species). In addition to killing the prey, part of the function of a haemotoxic venom for some animals is to aid digestion. The venom breaks down protein in the region of the bite, making prey easier to digest.

The process by which a haemotoxin causes death is much slower than that of aneurotoxin.Snakes which envenomate a prey animal may have to track the prey as it flees. Typically, amammalianprey will stop fleeing not because of death, but due to shock caused by the venomous bite. Symptoms are dependent upon species, size, location of bite and the amount of venom injected. In humans, symptoms include nausea, disorientation, and headache; these may be delayed for several hours.

Haemotoxins are used indiagnosticstudies of thecoagulationsystem.Lupus anticoagulantis detected by changes in thedilute Russell's viper venom time,which is alaboratoryassay based on—as its name indicates—venom of theRussell's viper.

External links

• Introduction to the special edition ofJournal of Toxicology - Toxin Reviews,21(1 & 2)