title: Preconditioning of the response to ischemia/ reperfusion-induced plasma leakage in hamster cheek pouch microcirculation.
abstract: OBJECTIVE
  Ischemic preconditioning and some drugs can protect tissues from injury by preserving microcirculation. This study evaluated vascular permeability in a hamster cheek pouch preparation using either short ischemic periods or bradykinin as preconditioning stimuli followed by 30 min of ischemia/reperfusion.
  
  
  METHODS
  Sixty-six male hamsters were divided into 11 groups: five combinations of different ischemic frequencies and durations (one, three or five shorts periods of ischemia, separated by one or five minutes) with 10 min intervals between the ischemic periods, followed by 30 min ischemia/reperfusion; three or five 1 min ischemic periods with 10 min intervals between them followed by the topical application of histamine (2 µM); bradykinin (400 nM) followed by 30 min of ischemia/reperfusion; and three control groups (30 min of ischemia/reperfusion or histamine or bradykinin by themselves). Macromolecular permeability was assessed by injection of fluorescein-labeled dextran (FITC-dextran, MW= 150 kDa; 250 mg/Kg body weight), and the number of leaks/cm2 was counted using an intravital microscope and fluorescent light in the cheek pouch.
  
  
  RESULTS
  Plasma leakage (number of leaks/cm²) was significantly reduced by preconditioning with three and five 1 min ischemic periods, one and three 5 min ischemic periods and by bradykinin. Histamine-induced macromolecular permeability was also reduced after three periods of 5 min of ischemia.
  
  
  CONCLUSIONS
  Short ischemic periods and bradykinin can function as preconditioning stimuli of the ischemia/reperfusion response in the hamster cheek pouch microcirculation. Short ischemic periods also reduced histamineinduced macromolecular permeability.
authors.affiliation: Laboratory for Clinical and Experimental Research on Vascular Biology, Biomedical Center, State University of Rio de Janeiro, RJ, Brazil.
authors.forename: Fabiana Gomes da
authors.initials: FG
authors.lastname: Conceição
authors.forename: Cristiane Maria Simonato
authors.initials: CM
authors.lastname: Conde
authors.forename: Erik
authors.initials: E
authors.lastname: Svensjö
authors.forename: Daniel Alexandre
authors.initials: DA
authors.lastname: Bottino
authors.forename: Eliete
authors.initials: E
authors.lastname: Bouskela
mesh_terms: D000818:Animals; D001920:Bradykinin / Q000494:pharmacology; D002199:Capillary Permeability / Q000187:drug effects*; D002610:Cheek / Q000098:blood supply; D006224:Cricetinae; D004195:Disease Models, Animal; D006632:Histamine / Q000494:pharmacology; D017442:Histamine Agonists / Q000494:pharmacology; D019194:Ischemic Preconditioning / Q000379:methods*; D008297:Male; D008833:Microcirculation; D010949:Plasma / Q000187:drug effects / Q000502:physiology; D015427:Reperfusion Injury / Q000097:blood / Q000188:drug therapy*; D013997:Time Factors; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D017442:Histamine Agonists; D014665:Vasodilator Agents; D006632:Histamine; D001920:Bradykinin