title: Role of medial smooth muscle cell function in antithrombogenicity of vein grafts.
abstract: OBJECTIVE
  To determine the significance of prostaglandin I2 (PGI2) production by medial smooth muscle cells (SMCs), we assessed PGI2 production from denuded vein grafts and their antithrombogenicity.
  
  
  METHODS
  A total of 30 dogs were divided into two groups: in group I, 14 dogs (27 veins, 188 segments) were used to assay PGI2 production, which was measured as 6-keto-PGF1 alpha. In group II, 16 dogs were used for an implantation study and the thrombus-free surface (TFS) score was calculated 24 h after implantation. Both groups contained the following subgroups: subgroup A, freshly harvested veins; subgroup B, endothelial denuded veins; subgroup C, veins frozen and cryopreserved; subgroup D, veins treated with protease.
  
  
  RESULTS
  Values of 6-keto-PGF1 alpha (pg/mg/min) for basal and stimulated states in subgroup I-A through I-D were 58.0 +/- 8.9 and 530.6 +/- 74.7, 26.3 +/- 4.7 and 82.3 +/- 11.4, 17.9 +/- 1.3 and 39.4 +/- 3.3, and 13.3 +/- 1.8 and 32.2 +/- 6.2, respectively. The PGI2 production in subgroup I-A were significantly higher than those in the other three subgroups (p < 0.01 for basal and stimulated), while the production in subgroup I-B was also significantly higher than those in the remaining two (p < 0.05 for basal and stimulated). The TFS scores in subgroup II-A through II-D were 98 +/- 2%, 90 +/- 2%, 38 +/- 5%, and 15 +/- 7%, respectively, showing significantly superior antithrombogenicity in subgroup II-B, as well as in II-A, when compared with the remaining two (p = 0.014).
  
  
  CONCLUSIONS
  The amount of PGI2 generated by the medial SMCs may be sufficient for maintaining the antithrombogenicity of the endothelial denuded AVGs.
authors.affiliation: First Department of Surgery, Asahikawa Medical College, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Yatsuyanagi
authors.forename: T
authors.initials: T
authors.lastname: Sasajima
authors.forename: K
authors.initials: K
authors.lastname: Goh
authors.forename: M
authors.initials: M
authors.lastname: Inaba
authors.forename: Y
authors.initials: Y
authors.lastname: Kubo
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000601:surgery; D004285:Dogs; D011464:Epoprostenol / Q000096:biosynthesis*; D005260:Female; D005342:Fibrinolysis; D066298:In Vitro Techniques; D008297:Male; D008855:Microscopy, Electron, Scanning; D009131:Muscle, Smooth, Vascular / Q000378:metabolism* / Q000648:ultrastructure; D011863:Radioimmunoassay; D011897:Random Allocation; D012016:Reference Values; D014182:Transplantation, Autologous; D014680:Veins / Q000378:metabolism* / Q000637:transplantation*
chemical_list: D011464:Epoprostenol