of the tube, filling it to a considerable degree.
In the case of vampire bats, the pistonlike motion of the batâs tongue causes blood to flow (via capillary action) along a pair of grooves located on the bottom of the tongue and directly into the batâs mouth. Thereâs even a cleft on the batâs lower lip and a space between its lower incisors to facilitate the blood flow. While feeding in this manner, saliva is constantly applied to the wound.
Vampire bat saliva contains several ingredients that inhibit the bodyâs normal clotting mechanisms. One such anticoagulant compound works by preventing blood platelets from clumping togetherâan important step in the formation of a plug that will eventually become a blood clot. Meanwhile, another salivary ingredient inhibits the torn blood vessels from constrictingâa process that normally reduces blood flow to the wound site and thus from the wound itself. Finally, an enzyme that medical researchers would christen desmokinase (and, later, desmoteplase or DSPA for
Desmodus rotundus
salivary plasminogen activator) breaks down the protein framework upon which the remainder of the blood clot forms.
Primarily because of its antihemostatic properties, vampire bat saliva has drawn considerable attention from the medical community as a potential treatment for certain strokes, namely, those in which a blood clot inhibits blood flow within the brainâs blood vessels. In these instances, cells in the region of the brain on the downstream side of the clot are denied oxygen and nutrients. If this blockade continues for long enough, the cells die and the function they were responsible for is impaired. Traditionally, stroke victims have been treated with a compound called tissue plasminogen activator (t-PA). Unfortunately, t-PA must be administered within three hours of the stroke to be effective. After that, the risk of bleeding into the brain increases, and as a result so does brain cell death. Since the average stroke patient waits more than twelve hours before going to the emergency room, t-PA is rarely administered and cannot be considered an effective treatment for the nationâs third-largest killer (after heart disease and cancer). Unlike t-PA, though, studies have shown that the vampire batâderived DSPA (an extremely potent clot buster) can be administered up to nine hours after a stroke has occurred and has no detrimental effects on brain cells.
Since vampire bats often lick the site
before
inflicting their bite, there has also been some speculation that their saliva might contain either a pain-killing agent that prevents their prey from feeling the bite, or an enzyme that could function to soften up the potential bite site. Even without a painkiller or a skin-softening enzyme, the vampire batâs razor-sharp teeth are likely capable of producing a wound that causes little or no pain to the prey.
In what amounts to a strange sort of payback, one modern technique used for vampire bat eradication involves the use of the anticoagulant warfarin. Isolated from a clover mold, warfarin has been marketed for humans since the 1950s as Coumadin. It remains (along with the lung-and intestine-derived compound heparin) a popular blood thinner for millions of patients prone to strokes or blood clots.
Vampire bats treated with warfarin are subject to no such medical benefits. After capturing the bats in mist nets, the animals are painted with a mixture of warfarin and Vaseline and then released so that they can fly back to their roosts. Since vampire bats spend a considerable amount of time grooming one another, the toxic paste is soon spread throughout the members of the roostâwith deadly results. Bats soon perish as the ingested warfarin induces massive internal hemorrhaging, causing them to bleed to death.
Although some might consider vampire bats dying from a clot-busting anticoagulant to be poetic justice, others might consider it to be a
In the case of vampire bats, the pistonlike motion of the batâs tongue causes blood to flow (via capillary action) along a pair of grooves located on the bottom of the tongue and directly into the batâs mouth. Thereâs even a cleft on the batâs lower lip and a space between its lower incisors to facilitate the blood flow. While feeding in this manner, saliva is constantly applied to the wound.
Vampire bat saliva contains several ingredients that inhibit the bodyâs normal clotting mechanisms. One such anticoagulant compound works by preventing blood platelets from clumping togetherâan important step in the formation of a plug that will eventually become a blood clot. Meanwhile, another salivary ingredient inhibits the torn blood vessels from constrictingâa process that normally reduces blood flow to the wound site and thus from the wound itself. Finally, an enzyme that medical researchers would christen desmokinase (and, later, desmoteplase or DSPA for
Desmodus rotundus
salivary plasminogen activator) breaks down the protein framework upon which the remainder of the blood clot forms.
Primarily because of its antihemostatic properties, vampire bat saliva has drawn considerable attention from the medical community as a potential treatment for certain strokes, namely, those in which a blood clot inhibits blood flow within the brainâs blood vessels. In these instances, cells in the region of the brain on the downstream side of the clot are denied oxygen and nutrients. If this blockade continues for long enough, the cells die and the function they were responsible for is impaired. Traditionally, stroke victims have been treated with a compound called tissue plasminogen activator (t-PA). Unfortunately, t-PA must be administered within three hours of the stroke to be effective. After that, the risk of bleeding into the brain increases, and as a result so does brain cell death. Since the average stroke patient waits more than twelve hours before going to the emergency room, t-PA is rarely administered and cannot be considered an effective treatment for the nationâs third-largest killer (after heart disease and cancer). Unlike t-PA, though, studies have shown that the vampire batâderived DSPA (an extremely potent clot buster) can be administered up to nine hours after a stroke has occurred and has no detrimental effects on brain cells.
Since vampire bats often lick the site
before
inflicting their bite, there has also been some speculation that their saliva might contain either a pain-killing agent that prevents their prey from feeling the bite, or an enzyme that could function to soften up the potential bite site. Even without a painkiller or a skin-softening enzyme, the vampire batâs razor-sharp teeth are likely capable of producing a wound that causes little or no pain to the prey.
In what amounts to a strange sort of payback, one modern technique used for vampire bat eradication involves the use of the anticoagulant warfarin. Isolated from a clover mold, warfarin has been marketed for humans since the 1950s as Coumadin. It remains (along with the lung-and intestine-derived compound heparin) a popular blood thinner for millions of patients prone to strokes or blood clots.
Vampire bats treated with warfarin are subject to no such medical benefits. After capturing the bats in mist nets, the animals are painted with a mixture of warfarin and Vaseline and then released so that they can fly back to their roosts. Since vampire bats spend a considerable amount of time grooming one another, the toxic paste is soon spread throughout the members of the roostâwith deadly results. Bats soon perish as the ingested warfarin induces massive internal hemorrhaging, causing them to bleed to death.
Although some might consider vampire bats dying from a clot-busting anticoagulant to be poetic justice, others might consider it to be a
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