title: In vivo gamma-rays induced initial DNA damage and the effect of famotidine in mouse leukocytes as assayed by the alkaline comet assay.
abstract: Ionizing radiation induces a variety of lesions in DNA, each of which can be used as a bio-indicator for biological dosimetry or the study of the radioprotective effects of substances. To assess gamma ray-induced DNA damage in vivo in mouse leukocytes at various doses and the effect of famotidine, blood was collected from Balb/c male mice after irradiation with 4 Gy gamma-rays at different time intervals post-irradiation. To assess the response, mice were irradiated with doses of gamma-rays at 1 to 4 Grays. Famotidine was injected intra-peritoneally (i.p) at a dose of 5 mg/kg at various time intervals before irradiation. Four slides were prepared from each sample and alkaline comet assay was performed using standard protocols. Results obtained show that radiation significantly increases DNA damage in leukocytes in a dose dependent manner (p < 0.01) when using appropriate sampling time after irradiation, because increasing sampling time after irradiation resulted in a time dependent disappearance of DNA damage. Treatment with only 5 mg/kg famotidine before 4 Gy irradiation led to almost 50% reduction in DNA damage when compared with those animals which received radiation alone. The radioprotective capability of famotidine might be attributed to radical scavenging properties and an anti-oxidation mechanism.
authors.affiliation: Dept. of Medical Genetics, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran. mozdarah@modares.ac.ir
authors.forename: Hossein
authors.initials: H
authors.lastname: Mozdarani
authors.forename: Borzo
authors.initials: B
authors.lastname: Nasirian
authors.forename: S Abolghasem
authors.initials: SA
authors.lastname: Haeri
mesh_terms: D000818:Animals; D000897:Anti-Ulcer Agents / Q000494:pharmacology; D020552:Comet Assay / Q000379:methods*; D004247:DNA / Q000737:chemistry; D004249:DNA Damage; D004260:DNA Repair / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D015738:Famotidine / Q000494:pharmacology*; D005720:Gamma Rays; D007962:Leukocytes / Q000187:drug effects* / Q000528:radiation effects*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011839:Radiation, Ionizing
chemical_list: D000897:Anti-Ulcer Agents; D015738:Famotidine; D004247:DNA