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Say 'Aaah' | Booster Shots

Vampire Bats Want to Thin Your Blood

October 30, 2000|Rosie Mestel

In spirit with the season, we'd like to say a couple of words about the noble vampire bat. Noble? Well, maybe not noble. But the bats, unlike the vast majority of animals, form favor-swapping friendships rather like human ones.

Say a bat is hungry because it didn't find a neck to bite that night. Well, another bat will spit up some of the blood it scored and give its famished pal a feed. Bat pals also hang out together and indulge in mutual grooming.

What's more, vampire bats inject an anesthetic so it won't hurt too much when they bite. How sweet. And their saliva contains a potent anticoagulant so the blood won't clot during the bat's leisurely, 20-minute feed. A few years back, Venezuelan scientist Rafael Apitz-Castro and colleagues managed to identify that anticoagulant, which they named . . . (drumroll) . . . draculin!

To learn more about draculin, we drew a pentagram and called upon the spirit of Apitz-Castro (OK, we e-mailed him). And we descended into the eerie catacombs of a local alchemists' lair (OK, the basement floor of the USC medical library) and found a 1995 research paper of his, published in Thrombosis and Haemostasis--a journal specializing in blood! blood! and more blood!

Here we read that scientists went into vampire bat caves in northwest Venezuela, got 20 bats to keep in captivity, fed them cow blood once a day and isolated their saliva with a drool-inducing drug called pilocarpine. Then they took that drool into a lab and separated out all the proteins in it till they found the one that does the anti-clotting trick.

Since draculin is a pretty powerful anticoagulant and works in a different way from other blood-thinners, it might well end up in the doctor's medicine bag one day. That's one reason why attendees of the 1998 International Bat Research Conference called on countries to help protect the bats and resort to bat control only when there's a problem with rabies or bats biting people and livestock. (

Learning all this was enough to make me want to go out and adopt a bat--and goshed if I didn't find an Adopt-A-Bat Web site ( You'll even get a snapshot and personal letter of thanks from your bat. But while I was sorely tempted by "Congo" the straw-colored fruit bat and "Yukon" the hoary bat, there are, alas, no vampire bats at this site.

Garlic and Blood: A Transylvanian Delight

Adopting a bat is one thing; having a creature--either real or supernatural--chomp into my vein and lap my blood is another. Will garlic help keep the fiends at bay? You can certainly find garlic-based products that claim they will repel all kinds of animals. And an article in the Journal of the American Medical Assn. earlier this year reported that garlic works quite well at repelling ticks--in fact, the authors, from Lund University in Sweden, suggest it might be used to help prevent Lyme disease in Sweden's armed forces.

Turns out Apitz-Castro and colleagues have investigated garlic as well (there is definitely a theme to his research). But be afraid. Be very afraid. Garlic, it appears, contains chemicals that can thin the blood.

"Vampires," says Apitz-Castro, "will be happy with people who eat garlic because it will be easier for them to suck their blood!"


If you have an idea for a topic, write or e-mail Rosie Mestel at L.A. Times, 202 W. 1st. St, Los Angeles, CA 90012, Boo!

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