Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 42 3 2004 06 15 198 204 S. Kabodanian Ardestani M. Mahmood Janlow A. Kariminia2 Z.Tavakoli 2015 09 28 Elevated amounts of free radicals due to ionizing radiation have damaging effects on the body. H2-receptor antagonists have potential oxygen radical scavenging properties. We tried to determine the effects of two H2-receptor antagonists (cimetidine and ranitidine) on lipid peroxidation (LPO) and lipid profile (LP) in plasma and liver of γ-irradiated (1Gy/day for 3 days) BALB/c mice. The control group of mice were fed with normal food and drinks but the experiment group of mice were fed control diet and drinking water, containing cimetidine or ranitidine (1mg/lit). After 3 days of supplementation, the animals were subjected to sublethal γ-radiation, which caused a significant increase in cholesterol level in experimental group (100% increase in comparison with the control group), but the amount of phospholipids did not change. The ratio of cholesterol to phospholipid showed a slight increase. Also γ-irradiation caused a significant increase in lipid fluorescence (11-48%), conjugated dienes (33-81%) in liver and increase in malondialdehyde (19-300%) in serum of mice who had received 1.09-3.1 Gy for 1-3 days. Cimetidine or ranitidine supplementation was able to restore the changes of LPO and LP in mice (1 Gy-radiated for 3 days). It is therefore concluded that the mice treated with cimetidine or ranitidine were able to tolerate biomembrane damages provoked by sublethal γ-radiation. This supports the hypothesis that cimetidine or ranitidine may afford an efficient protection against ionizing radiation or diseases that are characterized by in vivo free radical-mediated oxidative stress mechanisms. https://acta.tums.ac.ir/index.php/acta/article/view/2719 https://acta.tums.ac.ir/index.php/acta/article/download/2719/2701