title: Low dose gamma-irradiation differentially modulates antioxidant defense in liver and lungs of Balb/c mice.
abstract: OBJECTIVE
  To evaluate the effect of low-dose (<50 cGy) whole body ?-irradiation on the antioxidant defense system in the liver and the lungs of mice at various post-irradiation intervals.
  
  
  METHODS
  Male Balb/c mice, 5 - 6 weeks of age, were divided into irradiated and non-irradiated groups. Whole body irradiation was done with gamma-rays from a (60)Co source at doses of 10, 25 and 50 cGy (48.78 cGy/min). Lipid peroxidation and antioxidant status were measured in the liver and the lungs at 4, 12 and 24 h after irradiation.
  
  
  RESULTS
  Lipid peroxidation increased by 1.38 and 2.0 fold in lung and liver respectively at 12 h after exposure to 25 cGy. Whole body exposure to 25 and 50 cGy significantly (p < 0.05) increased the hepatic reduced glutathione at 4 h. Reduced glutathione continued to rise until 12 h and returned to the basal level at 24 h, whereas in the lungs it remained elevated until 24 h at 10 and 25 cGy. Antioxidant enzymes activities for superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase increased by 1.22, 1.13, 1.22 and 1.11 fold respectively (p < 0.05) in the liver at 4 h after exposure to 50 cGy and remained elevated at almost the same level up to 12 h after exposure. Surprisingly these antioxidant defense enzymes remained unaltered in the lung at the above radiation doses.
  
  
  CONCLUSIONS
  Low-dose whole body gamma-irradiation differentially modulates the antioxidant defense system in the liver and lungs of mice. The induction of endogenous glutathione, immediately after exposure to low-dose -irradiation, may be beneficial in protecting the cells from reactive oxygen species (ROS) induced oxidative stress.
authors.affiliation: Departments of Biophysics, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.
authors.forename: P K
authors.initials: PK
authors.lastname: Avti
authors.forename: C M
authors.initials: CM
authors.lastname: Pathak
authors.forename: S
authors.initials: S
authors.lastname: Kumar
authors.forename: G
authors.initials: G
authors.lastname: Kaushik
authors.forename: T
authors.initials: T
authors.lastname: Kaushik
authors.forename: A
authors.initials: A
authors.lastname: Farooque
authors.forename: K L
authors.initials: KL
authors.lastname: Khanduja
authors.forename: S C
authors.initials: SC
authors.lastname: Sharma
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays / Q000009:adverse effects*; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D015227:Lipid Peroxidation; D008099:Liver / Q000528:radiation effects; D008168:Lung / Q000528:radiation effects; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D013482:Superoxide Dismutase / Q000378:metabolism; D014916:Whole-Body Irradiation / Q000009:adverse effects*
chemical_list: D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005980:Glutathione Reductase