title: Possible role of platelet-activating factor in the in vivo expression of tissue factor in neutrophils.
abstract: BACKGROUND
  Recently, we demonstrated that neutrophils express tissue factor (TF) in a model of acute obstructive cholangitis (AOC). However, the regulation of TF expression was not clear. In this study, we clarified the role of platelet-activating factor (PAF) in TF expression in neutrophils.
  
  
  METHODS
  In a model of AOC, intravenous PAF antagonist, (SM-12502, 200 mg/kg) was administered 5 min before sepsis was induced. Normal saline was given as a control. Coagulation parameters and TF activity were monitored for 6 h. Thereafter, the liver was harvested for histological examination.
  
  
  RESULTS
  The percentage of neutrophils which stained positive for TF was significantly reduced by SM-12502 (74.9 +/- 19.3% vs 96.3 +/- 2.8%) (P < 0.01). The number of leukocytes infiltrating the liver was also significantly reduced. Coagulation abnormalities, TF activity, and focal necrosis of the hepatocytes were reduced by SM-12502.
  
  
  CONCLUSIONS
  SM-12502 inhibits TF expression in neutrophils which have infiltrated the liver sinusoids, reducing the subsequent infiltration of leukocytes. These results suggest that PAF plays an important role in the expression of TF in neutrophils in vivo.
authors.affiliation: Department of Surgery 1, University of Occupational and Environmental Health, Kitakyushu, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Todoroki
authors.forename: A
authors.initials: A
authors.lastname: Higure
authors.forename: K
authors.initials: K
authors.lastname: Okamoto
authors.forename: K
authors.initials: K
authors.lastname: Okazaki
authors.forename: Y
authors.initials: Y
authors.lastname: Nagafuchi
authors.forename: S
authors.initials: S
authors.lastname: Takeda
authors.forename: H
authors.initials: H
authors.lastname: Katoh
authors.forename: H
authors.initials: H
authors.lastname: Itoh
authors.forename: K
authors.initials: K
authors.lastname: Ohsato
authors.forename: S
authors.initials: S
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D001777:Blood Coagulation; D002761:Cholangitis / Q000097:blood / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D007962:Leukocytes / Q000473:pathology; D008099:Liver / Q000473:pathology; D008297:Male; D009504:Neutrophils / Q000378:metabolism* / Q000473:pathology; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011817:Rabbits; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines; D013925:Thromboplastin / Q000378:metabolism*
chemical_list: D010972:Platelet Activating Factor; D013844:Thiazoles; D053778:Thiazolidines; C065776:3,5-dimethyl-2-(3-pyridyl)thiazolidin-4-one; D013925:Thromboplastin; D001219:Aspartate Aminotransferases