title: Consequences of lethal-whole-body gamma radiation and possible ameliorative role of melatonin.
abstract: Gamma radiation induces the generation of free radicals, leading to serious cellular damages in biological systems. Radioprotectors act as prophylactic agents that are administered to shield normal cells and tissues from the deleterious effects of radiation. Melatonin synergistically acts as an immune-stimulator and antioxidant. We investigated the possible radioprotective role of melatonin (100 mg/kg i.p.) against lethal-whole-body radiation- (10 Gy) induced sickness, body weight loss, and mortality in rats. Results of the present study suggest that exposure to lethal-whole-body radiation incurred mortality, body weight loss, and apoptosis and it also depleted the immunity and the antioxidant status of the rats. Our results show that melatonin pretreatment provides protection against radiation induced mortality, oxidative stress, and immune-suppression. The melatonin pretreated irradiated rats showed less change in body weight as compared to radiation only group. On the other hand, melatonin appeared to have another radioprotective role, suggesting that melatonin may reduce apoptosis through a caspase-3-mediated pathway by blocking caspase-3 activity.
authors.affiliation: Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Ehsan
authors.initials: E
authors.lastname: Mihandoost
authors.affiliation: Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Shirazi
authors.affiliation: Department of Medical Physics, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors.forename: Seied Rabie
authors.initials: SR
authors.lastname: Mahdavi
authors.affiliation: Department of Radiology and Medical Physics, Faculty of Paramedicine, Kashan University of Medical Sciences, Kashan, Iran.
authors.forename: Akbar
authors.initials: A
authors.lastname: Aliasgharzadeh
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000528:radiation effects; D001835:Body Weight; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D002374:Catalase / Q000378:metabolism; D005720:Gamma Rays / Q000009:adverse effects*; D015870:Gene Expression / Q000528:radiation effects; D005979:Glutathione Peroxidase / Q000378:metabolism; D007113:Immunity, Innate / Q000528:radiation effects; D008214:Lymphocytes / Q000276:immunology / Q000473:pathology / Q000528:radiation effects; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D018384:Oxidative Stress / Q000528:radiation effects; D011832:Radiation Injuries / Q000209:etiology / Q000276:immunology / Q000401:mortality / Q000517:prevention & control*; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D016019:Survival Analysis; D014916:Whole-Body Irradiation
chemical_list: D000975:Antioxidants; D011837:Radiation-Protective Agents; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D053148:Caspase 3; D008550:Melatonin