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The Scientific World Journal
Volume 2014, Article ID 621570, 9 pages
Research Article

Consequences of Lethal-Whole-Body Gamma Radiation and Possible Ameliorative Role of Melatonin

1Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
2Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
3Department of Medical Physics, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran
4Department of Radiology and Medical Physics, Faculty of Paramedicine, Kashan University of Medical Sciences, Kashan, Iran

Received 2 July 2014; Revised 7 September 2014; Accepted 8 October 2014; Published 5 November 2014

Academic Editor: Andreas K. Nussler

Copyright © 2014 Ehsan Mihandoost et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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.