Vampire bats

Liheratore GT, Samson A, Bladin C, Schleuning WD, Medcalf RL. Vampire bat salivary plasminogen activator (desmoteplase) A unique fibrinolytic enzyme that does not promote neurodegeneration. Stroke. 2003 34 537-543. 

New-Generation Agents Desmoteplase is a genetically engineered version of the clot-dissolving factor found in the saliva of the vampire bat Desmodus rotundas. 

Figure 8 Venomous animals with chemotherapeutic potential, (a) Vampire bat (Desmodus rotundas (http // www.Animalpicturesarchive.com)) (b) medicinal leech [Hirudo medicinalis)-, (c) oriental fire-bellied toad (Bombina orientalis)-, (d) phantasmal poison frog [Epipedobates tricolor), (e) solitary tunicate sea peach Halocynthia aurantium), (f) glia monster (Heloderma suspectum). Photos (b)-(f) by I. Boyd (Creative Commons Attribution ShareAlike License), H. Van (Public domain), L. Ghoul (Creative Commons Attribution ShareAlike License), A. Rode (Creative Commons Attribution ShareAlike License) and Arpingstone (Public domain), respectively. See website for photo credit (a).

In comparison, the vampire bat has a capacity for urea synthesis approximately 1000-fold greater than that of a human. A bat consumes one half of its weight in blood in 10-15 minutes so that the massive amount of protein that is metabolised produces a massive amount of ammonia which must be removed as quickly as possible. Indeed, it also ingests sufficient fluid so that it is too heavy to fly. Hence, it urinates very quickly. 

A complex biologically relevant odor, such as that of a fruit for fruit bats, may require fewer molecules overall for detection than each of its single components alone (Laska 1990 Laska and Hudson, 1991). Vampire bats (P/asmodws... 

Turning to a mammalian parasite, the vampire bat, Desmodus rotundus, is very sensitive to butyric acid, a common compound given ofFby mammals. It detects 0.0039-0.00784 % (vol.) butyric acid. This is lower than the hmnan threshold (Schmidt and Greenhall, 1971). 

This is another major protozoal disease of domestic animals prevalent primarily in tropical Africa. The infection is mainly transmitted by tsetse flies, though salivarian or stercoranian methods of infection are also known. Some blood sucking insects such as Tabanus and Stomoxys flies, and also vampire bats may transmit trypanosomiasis in animals. Infections with Trypanosoma equiperdum in horses and donkeys may also be transmitted during coitus. 

Warner CK, Zaki SR, Shieh WJ, et al. Laboratory investigation of humans from vampire bat rabies in Peru. Am J Prop Med Hyg. 1999 60 502-507. 

Kratzschmar, J., et al.. The plasminogen activator family from the salivary gland of the vampire bat Desmodus rotundus cloning and expression. Gene, 1991. 105(2) p. 229-37. 

Schleuning, W.D., Vampire bat plasminogen activator DSPA-alpha-1 (desmoteplase) a thrombolytic drug optimized by natural selection. Haemostasis, 2001. 31(3-6) p. 118-22. 

Bringmann, R, et al.. Structural features mediating fibrin selectivity of vampire bat plasminogen activators. J Biol Chem, 1995. 270(43) p. 25596-603. 

MeUott, M.J., et al.. Vampire bat salivary plasminogen activator promotes rapid and sustained reperfusion without concomitant systemic plasminogen activation in a canine model of arterial thrombosis. Arterioscler Thromb, 1992. 12(2) ... 

Toschi, L., et al.. Fibrin selectivity of the isolated protease domains of tissue-type and vampire bat salivary gland plasminogen activators. EurJ Biochem, 1998. 252(1) p. 108-12. 

There is no doubt, however, that vampire bats exist. Most bats feast on insects, and they are excellent pest eradicators, but vampire bats tend to be pests themselves. These tropical creatures feed at night, lapping up the blood that flows from small incisions they make in their prey with their sharp teeth. Usually, the victim — a cow, say — isn t even disturbed by the bite. On occasion, a vampire bat will prey on a human, perhaps... 

One of the problems with this treatment is that it not only dissolves existing blood clots but also prevents clot formation. This translates into an increased risk of internal bleeding. It seems that bat-PA may be superior to the currently used substance, t-PA, because it is capable of dissolving existing clots without impairing the blood s ability to coagulate if necessary. So, who knows Someday, hospitals may stock vampire bats. But they ll have to keep them away from the blood bank. 

Death from mining accidents in Columbia, increased prevalence of malaria in Brazil, and increased frequency of attacks by rabid vampire bats (Desmodus rotundas) in Venezuela are documented. 

HOW VAMPIRE BATS SEE IN THE DARK, AND HOW THE PANDA LOST ITS TASTE FOR MEAT... 

Through fast and fluid evolution, the sensory apparatus connected to neurons quickly developed sensitivity to different aspects of the environment. At the creepy end of the spectrum of senses, vampire bats can sense hot blood in the darkbecause of ion channel evolution. Just like electric fish duplicated sodium channels to gain an electric sense, vampire bats duplicated ion channels to gain an infrared heat vision sense. 

Vampire bats started the process with a normal heat-sensitive calcium channel. You have this channel in your fingertips, when you touch something well above 100°F, opening the door to a calcium-wave signal. This channel is also found in tongue nerve cells where it responds to, say, hot soup. (The same channel opens when the chili-pepper molecule capsaicin binds to it, which is why these peppers taste hot —they are literally sending the hot signal.)... 

Vampire bats repurposed this hot-sensing channel into a warm-sensing channel by cutting off a part of the gene so that the channel protein is incomplete and unstable. Because it is shghtly broken, the vampire bat s channel opens more easily, at temperatures down to about 85°F. This channel activates when it is pointed toward the heat of a warm-blooded creature, like a human at 98.6°F. The bat turns a broken protein into a sixth sense. 

Vampires are, of course, fictional, and are based on the original novel by Bram Stoker. But vampire bats do exist in South America, and survive almost exclusively on a diet of blood, usually from cattle or livestock, not humans. Blood is a rich source of protein and iron, and even forms part of traditional dishes in many countries. In the United Kingdom, there is black pudding which is fried pig blood mixed with oatmeal, and in Germany, there is Blutwurst (blood sausage) which is made from pig s blood mixed with fillers such as barley. The Masai tribe of Tanzania drink the blood... 

Schmidt (eds). Natural History of Vampire Bats (GRG Press, Boca Raton, FL, 1988). (Vampire bats)... 

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