title: Nutritional supplementation with L-arginine prevents pelvic radiation-induced changes in morphology, density, and regulating factors of blood vessels in the wall of rat bladder.
abstract: OBJECTIVE
  To determine whether L-arginine has protective effects against radiation-induced alterations in the morphology and regulatory factors of vesical blood vessels in rats.
  
  
  METHODS
  Male rats aged 3-4 months were divided into groups of 10 animals each: (a) controls, consisting of non-treated animals; (b) radiated-only rats; and (c) radiated rats receiving L-arginine supplementation. Radiation was in one session of 10 Gy and was aimed at the pelvic-abdominal region. L-arginine was administered once a day (0.65 g/kg body weight), starting 7 days before radiation and continuing until killing on the 16th day after radiation. The density, relative area, and wall thickness of blood vessels were measured in the vesical lamina propria using histological methods, and the expression of vascular endothelial growth factor (VEGF) and fibroblast growth factors (FGF) in the bladder wall was assessed by RT-PCR.
  
  
  RESULTS
  Compared with controls, radiation alone decreased the density and relative area of blood vessels by 32 % (p < 0.01) and 25 % (p < 0.05), respectively, and reduced the arterial wall thickness by 42 % (p < 0.004). VEGF and FGF mRNA levels after radiation were diminished by 67 % (p < 0.002) and 56 % (p < 0.04), respectively. The radiated animals supplemented with L-arginine were not significantly different from controls.
  
  
  CONCLUSIONS
  Pelvic radiation leads to significant vesical modifications, as in the morphology of blood vessels and in VEGF and FGF expression. All these changes, however, were prevented by L-arginine treatment. These results emphasize, therefore, the potential use of this amino acid as a radioprotective drug.
authors.affiliation: Urogenital Research Unit, State University of Rio de Janeiro, Av. 28 de Setembro, 87, fundos, Rio de Janeiro, RJ, 20562-030, Brazil.
authors.forename: Waldemar S
authors.initials: WS
authors.lastname: Costa
authors.forename: Monica N
authors.initials: MN
authors.lastname: Ribeiro
authors.forename: Luiz E M
authors.initials: LE
authors.lastname: Cardoso
authors.forename: Maria C
authors.initials: MC
authors.lastname: Dornas
authors.forename: Cristiane F
authors.initials: CF
authors.lastname: Ramos
authors.forename: Carla B M
authors.initials: CB
authors.lastname: Gallo
authors.forename: Francisco J B
authors.initials: FJ
authors.lastname: Sampaio
mesh_terms: D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000627:therapeutic use*; D001808:Blood Vessels / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D019587:Dietary Supplements; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D008297:Male; D023421:Models, Animal; D009092:Mucous Membrane / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D010388:Pelvis / Q000528:radiation effects; D012333:RNA, Messenger / Q000378:metabolism; D011833:Radiation Injuries, Experimental / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D011837:Radiation-Protective Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D001743:Urinary Bladder / Q000098:blood supply* / Q000528:radiation effects; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D011837:Radiation-Protective Agents; D042461:Vascular Endothelial Growth Factor A; D005346:Fibroblast Growth Factors; D001120:Arginine