title: Heparin fails to inhibit the leukocyte recruitment for an extended time following inflammatory stimulus.
abstract: BACKGROUND
  Several studies have shown that heparin is able to inhibit leukocyte recruitment during an early acute inflammatory response. However, considering the pharmacokinetic aspects of heparin and the dynamics of inflammation our objective was to determine if heparin is able to retain its antimigratory property during a prolonged inflammatory response.
  
  
  OBJECTIVE
  Compare the effect of heparin on leukocyte recruitment to the peritoneal cavity during early acute inflammatory response and for a longer time post-inflammatory stimulus.
  
  
  METHODS
  Wistar rats pre-treated with subcutaneous heparin in doses of 1, 5, and 15 µg/kg were challenged with 2 mL intraperitoneal thioglycollate. After 3 or 8 h, the animals were killed. The cells in the peritoneal cavity were collected and counted. For differential counting, cells from peritoneal lavage and from blood were distended over a glass slide, stained, and counted.
  
  
  RESULTS
  After 3 h, heparin inhibited cell influx to the injury site at all tested dosages. The largest effect was achieved at a 5 µg/kg dose (83% of reduction, p < 0.001). After 8 h, heparin at a 1 µg/kg dose reduced 63% of cellular infiltration (p < 0.001); the group treated with a 15 µg/kg dose presented an pro-inflammatory effect observed by the higher proportions, when compared with the thioglycollate group, of neutrophils on whole blood (60.9%, p < 0.001) and peritoneal fluid (27.3%, p < 0.05), and whole blood monocytes (117.8%, p < 0.01).
  
  
  CONCLUSIONS
  These findings show that the heparin effect on leukocyte recruitment varies depending on its dosage and the duration of the inflammation.
authors.affiliation: Departamento de Bioquímica, Universidade Federal do Rio Grande do Norte (UFRN) , Natal, RN , Brazil and.
authors.forename: Dayse Santos
authors.initials: DS
authors.lastname: Arimateia
authors.forename: Adriana
authors.initials: A
authors.lastname: da Silva Brito
authors.forename: Fernanda Marques
authors.initials: FM
authors.lastname: de Azevedo
authors.forename: Giulianna Paiva Viana
authors.initials: GP
authors.lastname: de Andrade
authors.forename: Suely Ferreira
authors.initials: SF
authors.lastname: Chavante
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology*; D002634:Chemotaxis, Leukocyte / Q000187:drug effects* / Q000276:immunology; D004804:Eosinophils / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D006493:Heparin / Q000494:pharmacology*; D007958:Leukocyte Count; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D010529:Peritoneal Cavity / Q000166:cytology; D010533:Peritoneal Lavage; D010538:Peritonitis / Q000139:chemically induced / Q000276:immunology*; D017208:Rats, Wistar; D013864:Thioglycolates / Q000494:pharmacology; D013997:Time Factors
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D013864:Thioglycolates; D006493:Heparin
keywords: Antimigratory property; peritonitis; thioglycollate