Semin Thromb Hemost 1996; 22(3): 273-278
DOI: 10.1055/s-2007-999019
Copyright © 1996 by Thieme Medical Publishers, Inc.

Platelet Aggregation and Coagulation Inhibitors in Leech Saliva and Their Roles in Leech Therapy

Meir Rigbi, Miriam Orevi, Amiram Eldor
  • From the Department of Biological Chemistry, Institute of Life Sciences, The Hebrew University of Jerusalem, and Institute of Hematology, E. Sourasky Medical Center and The Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
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Publication History

Publication Date:
06 February 2008 (online)

Abstract

Prolonged bleeding by the host after the leech ceases to feed and several reports that the use of leeches restores blood flow in the microcirculation after plastic surgery led us to search for inhibitors of platelet aggregation in Hirudo medicinalis saliva. Dilute leech saliva was collected by phagostimulating starved leeches with a solution of arginine in saline. The saliva is shown to inhibit human platelet aggregation induced by thrombin, collagen, adenosine diphosphate (ADP), epinephrine, platelet activating factor (1-O-alkyl-2-acetyl-sn-3-glycerophophoryl choline [PAF]), and arachidonic acid. We have isolated the PAF inhibitor and found it to be an amphipathic phosphoglyceride. We have also purified apyrase adenosine triphosphate ([ATP] diphosphohydrolase), which inhibits ADP-induced platelet aggregation, and have described collagenase. Besides well-known hirudin, Hirudo saliva contains a potent inhibitor of coagulation factor Xa. We also report antiaggregant and anticoagulant activities in the crop content of the closely related Nile leech, Limnatis nilotica. Anticoagulants of hematophagous species are surveyed. We have used medicinal leeches in plastic surgery for decompression of skin flaps and in patients with postphlebitic syndrome and peripheral arterial occlusions. Preliminary results indicate certain beneficial effects of leech therapy.