title: The effect of 30-day pretreatment with pentoxifylline on the survival of a random skin flap in the rat: an ultrastructural and biomechanical evaluation.
abstract: BACKGROUND
  The aim of this study was to clarify the histological, ultrastructural and biomechanical effects of pentoxifylline (PTX) on the survival of random skin flaps (RSFs) in rats.
  
  
  METHODS
  Thirty male rats were randomly divided into experimental, sham and control groups. The experimental group received PTX 20 mg/kg/day, and the sham group received saline. A 20x70-mm RSF was made 30 days after the commencement of treatment for the three groups. PTX and saline were continued postoperatively for 7 days in the experimental and sham groups, respectively. On the seventh postoperative day, the surviving parts of the flaps were determined and examined through light and transmission electron microscopes. The wounds (incisions) on the margins of the flaps were evaluated histologically and biomechanically.
  
  
  RESULTS
  Analysis of variance showed that, in the experimental group, the mean of the surviving parts of the RSFs, fibroblast proliferation, collagen organization and granulation tissue of the wounds was significantly higher than in the sham and control groups (P=0.007, P=0.001, P=0.041, P=0.000, respectively). There were swollen mitochondria in the endothelium of the blood vessels of the surviving flap parts in the control and sham groups, whereas in the experimental group the mitochondria were normal.
  
  
  CONCLUSIONS
  Thirty days of pretreatment of RSFs with PTX significantly increased the survival of the flaps. PTX appeared to have healed wounds and reversed ultrastructural changes resulting from hypoxia in the blood vessel endothelium of the flaps.
authors.affiliation: Cell and Molecular Biology Research Center, Shaheed Beheshti University of Medical Sciences, Tehran, Iran. bayat_m@yahoo.com
authors.forename: Mohammad
authors.initials: M
authors.lastname: Bayat
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Chelcheraghi
authors.forename: Abbas
authors.initials: A
authors.lastname: Piryaei
authors.forename: Mohammad
authors.initials: M
authors.lastname: Rakhshan
authors.forename: Zhaleh
authors.initials: Z
authors.lastname: Mohseniefar
authors.forename: Fatemesadat
authors.initials: F
authors.lastname: Rezaie
authors.forename: Maryam
authors.initials: M
authors.lastname: Bayat
authors.forename: Hashem
authors.initials: H
authors.lastname: Shemshadi
authors.forename: Yousef
authors.initials: Y
authors.lastname: Sadeghi
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001808:Blood Vessels / Q000648:ultrastructure; D004730:Endothelium, Vascular / Q000648:ultrastructure; D006085:Graft Survival / Q000187:drug effects*; D006401:Hematologic Agents / Q000008:administration & dosage*; D008297:Male; D046529:Microscopy, Electron, Transmission; D008933:Mitochondrial Swelling; D010431:Pentoxifylline / Q000008:administration & dosage*; D051381:Rats; D012867:Skin / Q000098:blood supply / Q000648:ultrastructure*; D013524:Surgical Flaps
chemical_list: D006401:Hematologic Agents; D010431:Pentoxifylline