title: The effects of zinc sulfate on the levels of some elements and oxidative stress occurring in lenses of rats exposed to total cranium radiotherapy.
abstract: OBJECTIVE
  There is currently substantial clinical interest in zinc (Zn) as an antioxidant and a protective agent against radiation-related normal tissue injury. To further assess the potential antioxidative effects, the effects of Zn were studied in rat lenses, a model of radiation-induced oxidative stress.
  
  
  METHODS
  Sprague-Dawley rats were divided into three equal groups. Group 1 received neither Zn nor irradiation (control group). Group 2 (RT group) and 3 (RT+Zn group) were exposed to total cranium irradiation of 5 Gy in a single dose by using a cobalt-60 teletherapy unit. In addition to irradiation, group 3 was administered 10 mg/kg/day Zn. At the end of 10 days, the rats were killed. Their eyes were enucleated to measure the activities of antioxidant enzymes and the levels of iron, calcium, sodium and potassium.
  
  
  RESULTS
  Irradiation significantly increased malondialdehyde levels as an end product of lipid peroxidation, glutathione peroxidase activity, and iron and calcium concentrations. Irradiation decreased super-oxide dismutase activities and zinc concentrations in the rat lens, indicating an increased oxidative stress generated by the decomposition of water and/or Fenton reaction. Malondialdehyde levels and iron and calcium concentrations were significantly decreased, and superoxide dismutase and glutathione peroxidase activities and zinc concentrations were increased, in the rat lenses of the RT+Zn group. No differences were detected in any final measurement of sodium and potassium in the direct comparison among all groups.
  
  
  CONCLUSIONS
  Zinc, acting as an antioxidant agent, may protect the lens from radiation-induced injury by improving oxidative stress generated by the decomposition of water and/or Fenton reaction.
authors.affiliation: Atatürk University, Faculty of Medicine, Department of Radiation Oncology, Erzurum, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Kandaz
authors.affiliation: Atatürk University, Faculty of Medicine, Department of Radiation Oncology, Erzurum, Turkey.
authors.forename: Mustafa Vecdi
authors.initials: MV
authors.lastname: Ertekin
authors.affiliation: Atatürk University, Faculty of Medicine, Department of Radiation Oncology, Erzurum, Turkey.
authors.forename: Burak
authors.initials: B
authors.lastname: Erdemci
authors.affiliation: Atatürk University, Faculty of Medicine, Department of Biochemistry, Erzurum, Turkey.
authors.forename: Ahmet
authors.initials: A
authors.lastname: Kızıltunç
authors.affiliation: Atatürk University, Faculty of Medicine, Department of Ophthalmology, Erzurum, Turkey.
authors.forename: İbrahim
authors.initials: İ
authors.lastname: Koçer
authors.affiliation: Atatürk University, Faculty of Medicine, Department of Radiation Oncology, Erzurum, Turkey.
authors.forename: Hilal Kızıltunç
authors.initials: HK
authors.lastname: Özmen
authors.affiliation: Atatürk University, Faculty of Medicine, Department of Radiation Oncology, Erzurum, Turkey.
authors.forename: Meryem Işık
authors.initials: MI
authors.lastname: Aktan
authors.affiliation: Atatürk University, Faculty of Chemical Engineering, Department of Chemistry, Erzurum, Turkey.
authors.forename: Ayşe Vildan
authors.initials: AV
authors.lastname: Beşe
keywords: Antioxidant enzymes; Oxidative stress; Radiotherapy; Trace elements; Zinc sulfate