title: Modulation of gamma-ray-induced apoptosis in human peripheral blood leukocytes by famotidine and vitamin C.
abstract: To study the radioprotective effects of vitamin C and famotidine against radiation-induced apoptosis in human peripheral blood leukocytes, peripheral blood was obtained from six healthy volunteers including three males and three females. Twelve microlitres of blood sample diluted in 1 ml complete RPMI-1640 medium was irradiated with various doses of gamma-rays (4, 8 and 12 Gy) in the presence or absence of various doses of vitamin C and famotidine. After 48 and 72 h incubation in a 37 degrees C CO(2) incubator, neutral comet assay was performed for all samples. At least 1000 cells were analyzed for each sample for presence of apoptosis. Data were statistically evaluated using Mann-Whitney non-parametric and ANOVA tests. Results show a significant increase in apoptosis induction following gamma-irradiation with a dose dependent manner compared to controls (p<0.001). Presence of famotidine at 200 microg/ml produced a significant protective effect against radiation-induced apoptosis for various doses of radiation. Similar effects were observed for vitamin C at much lower doses (10 microg/ml). Dose reduction factor (DRF) calculated for famotidine treatment was about 1.5, and above 2 for vitamin C treatment. These results suggest that both vitamin C and famotidine suppresses radiation-induced apoptosis when used with various doses of gamma-irradiation (4-12 Gy) probably via *OH radical scavenging and an intracellular antioxidation mechanism.
authors.affiliation: Department of Medical Genetics, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran. mozdarah@modares.ac.ir
authors.forename: H
authors.initials: H
authors.lastname: Mozdarani
authors.forename: P
authors.initials: P
authors.lastname: Ghoraeian
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000975:Antioxidants / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects; D001205:Ascorbic Acid / Q000494:pharmacology*; D002478:Cells, Cultured; D020552:Comet Assay; D015738:Famotidine / Q000494:pharmacology*; D005260:Female; D005720:Gamma Rays; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects* / Q000528:radiation effects; D008297:Male; D013997:Time Factors
chemical_list: D000975:Antioxidants; D015738:Famotidine; D001205:Ascorbic Acid