title: Induction of radical scavenging ability and protection against radiation-induced damage to microsomal membranes following low-dose irradiation.
abstract: OBJECTIVE
  To investigate changes in rat liver cytosolic radical scavenging ability and in microsomal membrane function following low doses of radiation.
  
  
  METHODS
  Wistar rats were irradiated with 1-50 cGy of X-rays and liver cytosolic radical scavenging ability was determined using DPPH, a stable free radical. Liver microsomal drug metabolizing activity was determined using hexobarbital as a substrate. Cytosolic antioxidants and microsomal enzymes were spectrophotometrically determined.
  
  
  RESULTS
  Irradiation of rats at around 5-10 cGy induced liver cytosolic radical scavenging ability and a considerable increase in this ability at 5 cGy was observed for 3 days after irradiation. Glutathione reductase was suggested as a candidate of cytosolic antioxidants. Radiation-induced damage to liver microsomal drug metabolizing enzyme activity was suppressed by preirradiation with 5 cGy, mainly by protecting cytochrome P-450.
  
  
  CONCLUSIONS
  Low doses of radiation increased cytosolic radical scavenging ability and resulted in protection of microsomal membrane function which is easily damaged by radiation-induced free radicals.
authors.affiliation: Division of Biology and Oncology, National Institute of Radiological Sciences, Japan. yukawa@nirs.go.jp
authors.forename: O
authors.initials: O
authors.lastname: Yukawa
authors.forename: T
authors.initials: T
authors.lastname: Nakajima
authors.forename: M
authors.initials: M
authors.lastname: Yukawa
authors.forename: T
authors.initials: T
authors.lastname: Ozawa
authors.forename: T
authors.initials: T
authors.lastname: Yamada
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000528:radiation effects; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D008297:Male; D008862:Microsomes, Liver / Q000201:enzymology / Q000528:radiation effects*; D009249:NADP / Q000378:metabolism; D011835:Radiation Protection; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D017382:Reactive Oxygen Species; D009249:NADP; D003577:Cytochrome P-450 Enzyme System; D013482:Superoxide Dismutase