Effects of low-dose irradiation with x-rays and pi-mesons on embryos of two different mouse strains.

The effects of two different kinds of radiation (X-rays and negative pions) on embryonic development of mice was examined. The application of a known radiosensitizer (lucanthone) combined with 13.5 rd whole-body irradiation on day 8 of gestation showed enhanced teratogenic action compared to treatment with each of the agents alone. The extent of intensification varied both with mouse strain and treatment, indicating possible differences in repair capacity and LET-dependency of sensitization effects. Strain differences were found in the incidence and type of chemical and radiation-induced malformations, which may be explained by different developmental stages at the time of treatment.