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| A vampire bat drinks fresh cow blood at the ZooAmerica North American Wildlife Park in Hershey. Researchers are using enzymes taken from vampire bat saliva to develop a blood-clot-dissolving drug called Draculin to help stroke victims recover. |
Not far away, a Gila monster stared at visitors with cold eyes, looking far too mellow to grip a small animal with crushing intensity and inflict a venomous bite.
Not all the animals at ZooAmerica North American Wildlife Park in Hershey are cute creatures.
But instead of saying ick, think about how bats and Gila monsters might be just what the doctor ordered.
Researchers are using enzymes taken from vampire bat saliva to develop a blood-clot-dissolving drug called Draculin (yes, named after Count Dracula) to help stroke victims recover. Researchers also have learned that a component of Gila monster venom can reduce blood-glucose levels, something potentially helpful to diabetics, officials at ZooAmerica said.
“Scientists study many species to see how they can help people,” said Dale Snyder, ZooAmerica general curator. “We don’t have the animals here just because they are beautiful, but for benefits down the road, too. A lot of these species hold promise for researchers.”
Snyder and Elaine Gruin, ZooAmerica curator of education, this weekend are discussing characteristics of the ZooAmerica species during the zoo’s 25th annual community weekend of free admissions. The event, which includes free parking, continues from 10 a.m. to 4:30 p.m. today.
Standing near 19 vampire bats, Gruin said that only three of 1,000 bat species drink blood. Vampire bats — nocturnal, flying mammals — weigh about 2 ounces.
Gruin said that after the bats use their sharp incisor teeth to bite into flesh, an anticoagulant in the bat’s saliva lets the blood flow instead of clotting. The bat then uses its grooved tongue to drink the flowing blood.
Vampire bat saliva, rich in anticoagulants, could reopen clogged human blood vessels so that damage and even death from some strokes could be prevented, she said. Patient testing is under way.
Vampire bats need about two tablespoons of blood a night, which they usually get from domestic animals such as cows, pigs and horses.
“Vampire bats are found in Mexico, Central America and northern South America but not here,” she said. “They can drink blood for up to a half hour but spend a lot of their time hanging upside down.”
Although bats have a bad reputation, Gruin said they’re useful, too.
“They eat thousands of insects a night, which makes them nature’s bug zappers,” she said. “Some bats pollinate. Some eat fruit seeds, then drop them elsewhere.”
Pennsylvania has nine species of bats, none of them blood-drinkers.
Snyder held a Gila monster, a sluggish 2-pound, 18-inch-long lizard. Gila monsters and Mexican beaded lizards are the only venomous lizards of the 3,000 lizard species in the world. Gila monsters live in Arizona, southern California and Mexico.
“We have four Gila monsters,” Snyder said. “When they bite, they’re hard to get off because they clamp down. The venom glands are in the lower jaw.”
He said that the opening and closing of the mouth sends the venom into the saliva, along the grooved teeth and into the intended victim. The longer the lizard holds on, the more severe the venomous bite.
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