THROMBIN INHIBITORS OF BLOODSUCKING ANIMALS

Hematophagous animals have the unique ability to inhibit blood coagula tion when sucking blood from a wound, This article concerns thrombin i nhibitors from these animals, specifically the one from the insect Rho dnius prolixus. To date, the most-studied inhibitor from these animals is hirudin, which specifically neutralizes thrombin but no other clot ting serine proteases, The biochemical properties of hirudin are descr ibed, Hirudinlike thrombin inhibitors from the Asian leech Hirudo mani llensis, Haemadipsa sylvestris, and Haemadipsidae are also discussed, In addition, a thrombin inhibitor from the insect Rhodnius prolixus, R hodniin, is extensively reviewed, There is considerable interest in th ese inhibitors because they may be found useful as treatment modalitie s for thromboembolic disorders, Hirudin is already extensively investi gated, and some of the others may follow Potentially these new inhibit ors could be of greater clinical benefit than the presently used hepar ins.