title: Evaluation of the in vivo thrombolytic activity of a metalloprotease from Bothrops atrox venom using a model of venous thrombosis.
abstract: BACKGROUND
  Due to the importance of blood coagulation and platelet aggregation in brain- and cardiovascular diseases, snake venom proteins that interfere in these processes have received significant attention in recent years considering their potential to be used as models for new drugs.
  
  
  OBJECTIVE
  This study aimed at the evaluation of the in vivo thrombolytic activity of Batroxase, a P-I metalloprotease from Bothrops atrox venom.
  
  
  METHODS
  In vivo thrombolytic activity of Batroxase was tested on a model of venous thrombosis in rats, with partial stenosis of the inferior vena cava, and vessel wall injury with ferric chloride at 10% for 5 min. After formation of the thrombus, increasing amounts of Batroxase were administered intravenously. The prescription medication Alteplase (tissue-type plasminogen activator) was used as positive control for thrombolytic activity, while saline was used as negative control. Bleeding time was assessed with a tail bleeding assay.
  
  
  RESULTS
  Batroxase presented thrombolytic activity in vivo in a concentration-dependent manner, with 12 mg/kg of the metalloprotease causing a thrombus reduction of 80%, a thrombolytic activity very similar to the one observed for the positive control Alteplase (85%). The tail bleeding time was not altered by the administration of Batroxase, while it increased 3.5 times with Alteplase. Batroxase presented fibrinolytic and fibrinogenolytic activities in vitro, which were inhibited by alpha 2-macroglobulin.
  
  
  CONCLUSIONS
  Batroxase presents thrombolytic activity in vivo, thus demonstrating a possible therapeutic potential. The inactivation of the metalloprotease by alpha 2-macroglobulin may reduce its activity, but also its potential side effects, as seen for bleeding time.
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil. Electronic address: jacob_ferreira@yahoo.com.br.
authors.forename: Anna L
authors.initials: AL
authors.lastname: Jacob-Ferreira
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil.
authors.forename: Danilo L
authors.initials: DL
authors.lastname: Menaldo
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil.
authors.forename: Carolina P
authors.initials: CP
authors.lastname: Bernardes
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil.
authors.forename: Marco A
authors.initials: MA
authors.lastname: Sartim
authors.affiliation: Department of Pharmacology, Faculty of Medical Sciences, State University of Campinas (UNICAMP), Campinas, São Paulo, Brazil.
authors.forename: Célio D
authors.initials: CD
authors.lastname: de Angelis
authors.affiliation: Department of Pharmacology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil.
authors.forename: José E
authors.initials: JE
authors.lastname: Tanus-Santos
authors.affiliation: Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, São Paulo, Brazil. Electronic address: suvilela@usp.br.
authors.forename: Suely V
authors.initials: SV
authors.lastname: Sampaio
mesh_terms: D000818:Animals; D017837:Bothrops; D003435:Crotalid Venoms / Q000201:enzymology / Q000633:toxicity*; D004195:Disease Models, Animal; D008297:Male; D045726:Metalloproteases / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013927:Thrombosis / Q000517:prevention & control*
chemical_list: D003435:Crotalid Venoms; D045726:Metalloproteases
keywords: Alpha2-macroglobulin; Batroxase; Metalloproteases; Snake venom; Thrombolytic agents; Venous thrombosis