title: Radiation-induced apoptosis in mouse lymphocytes is modified by a complex dietary supplement: the effect of genotype and gender.
abstract: This study examined whether radiation sensitivity measured by lymphocyte apoptosis could be ameliorated by a complex anti-oxidant/anti-ageing dietary supplement. We also examined lymphocytes from both genders of normal (Nr) mice as well as transgenic growth hormone (Tg) mice that express strongly elevated reactive oxygen species processes and a progeroid syndrome of accelerated ageing. We introduce Tg mice as a potentially valuable new model to study radiation sensitivity. Isolated lymphocytes from all experimental groups were exposed to gamma radiation and the time course of apoptosis was measured in vitro. Kinetics of radiation-induced apoptosis was similar among groups, which peaked at 8 h, but maximal levels differed significantly between groups. Nr male mice had 60% lower levels of radiation-induced apoptosis than Tg males, supporting our hypothesis that Tg mice would be radiation sensitive. The dietary supplement protected lymphocytes in male mice of both strains, with proportionally greater reductions in Tg mice. Lymphocytes from female mice (both Nr and Tg) were highly radiation resistant compared to males and the supplement provided no additional benefit at the doses used in this study. These results highlight that radiation-induced apoptosis is complex and is modified by genotype, dietary supplements and gender.
authors.affiliation: Department of Medical Physics and Applied Radiation Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4K1, Canada. lemonja@mcmaster.ca
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Lemon
authors.forename: C David
authors.initials: CD
authors.lastname: Rollo
authors.forename: Nicole M
authors.initials: NM
authors.lastname: McFarlane
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Boreham
mesh_terms: D000818:Animals; D017209:Apoptosis; D004032:Diet; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D005720:Gamma Rays; D005838:Genotype; D008214:Lymphocytes / Q000528:radiation effects*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D018384:Oxidative Stress; D012737:Sex Factors