American Society of Hirudotherapy

Inhibition of in vitro clot growth by r-hirudin is more effective and longer sustained than by an analogous peptide

Research article published in Thrombosis and haemostasis (1994)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Observational studyDrug DevelopmentRomisch J et al. · Thrombosis and haemostasis, 1994

Abstract

The specific thrombin inhibitors r-hirudin and a synthetic peptide (I) D-FPRP(G)4-NGDFEEIPEEYL were compared in in vitro tests. r-hirudin proved to be the superior compound with respect to inhibition of amidolytic small substrate turnover that is catalysed by soluble and immobilised thrombin as well as to inhibition of fibrinogen activation. In an in vitro clot model significantly higher molar concentrations of peptide I are needed to achieve fibrin bound thrombin inhibition equivalent to that of r-hirudin. Stable complexes consisting of thrombin and hirudin oppose labile complexes containing the synthetic peptide. The latter leads to a regaining of thrombin activity with subsequent additional fibrin accretion. Analyses of the mixtures of thrombin and peptide I display a time dependent release of amino-terminal D-FPR peptide (III) exhibiting, similar to the residual fragment (peptide II), only weak inhibitory activity. Peptide I and the carboxy-terminal fragment induce, within a certain concentration range, an increase in thrombin activity and clot growth.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeComparative StudyJournal Article
Indexed MeSH termsAmino Acid SequenceBlood CoagulationFibrinHirudinsHumansMolecular Sequence DataPeptide FragmentsRecombinant ProteinsStructure-Activity RelationshipThrombinTime Factors

Summary

Inhibition of in vitro clot growth by r-hirudin is more effective and longer sustained than by an analogous peptide.

Why This Matters for Hirudotherapy

This study compared the specific thrombin inhibitors r-hirudin and a synthetic peptide (D-FPRP(G)4-NGDFEEIPEEYL) in in vitro tests of amidolytic substrate turnover, fibrinogen activation, and an in vitro clot model. r-Hirudin was the superior compound, forming stable thrombin–hirudin complexes, whereas the synthetic peptide formed labile complexes that allowed thrombin activity to resume and, within certain concentration ranges, even increased thrombin activity and clot growth. The findings highlight differences in complex stability and durability, but the abstract describes only 'in vitro tests' without specifying the blood source and does not involve live leeches or clinical outcomes; the relevance to hirudotherapy is limited to characterizing recombinant hirudin's properties.

Citation

Inhibition of in vitro clot growth by r-hirudin is more effective and longer sustained than by an analogous peptide

Romisch J et al. · Thrombosis and haemostasis, 1994

DOIPubMed

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