Lifetime study in mice for radiation-induced cataracts
Summary
We initiated a lifetime study in mice focusing on non-cancer effects after exposure to middle and low doses of ionizing radiation, particularly radiation-induced cataracts and retinal disorders.
Mice (males and females) were irradiated (0, 0.063, 0.125 and 0.5 Gy) and received in vivo examinations for lens opacities by Scheimpflug imaging monthly and for retinal effects by OCT every four months. To investigate the underlying mechanisms of radiation-induced effects mice are sacrificed at different time points (4 and 24 hours, 12, 18 and 24 months after irradiation) for pathological and histological examinations.
Beside wild-type mice, heterozygous Ercc2/Xpd mutants are included in the study to estimate the risk of genetic susceptibility in virtually healthy mutant mice, while homozygous Ercc2 mutants develop cortical cataracts at early age. The ERCC2 protein has DNA helicase activity and is involved in general transcription and DNA repair.
First analyses of the Scheimpflug examinations did not show significant changes within the groups up to 20 months after irradiation with 0 and 0.5 Gy, while OCT data showed a reduction of the retinal thickness in irradiated heterozygous mutants. This study is still in progress.
