Irradiation of male rats increases the chromosomal sensitivity of progeny to genotoxic agents.

Chromosomal sensitivity to genotoxic agents was studied in the first generation progeny of male rats irradiated at a dose of 4.5 Gy X-rays and in the progeny of non-exposed animals. The frequency of anaphase chromosome aberrations (bridges or/and fragments) in rats exposed to X-rays or treated with cyclophosphamide was estimated: in proliferating hepatocytes (2 Gy) as a function of time during liver regeneration after partial hepatectomy; in bone marrow cells (2.5 Gy or 25 mg/kg body wt); in fetal fibroblasts (3 Gy). The sensitivity of chromosomes to genotoxic agents was found to be increased in the progeny of irradiated male rats as compared with the progeny of non-exposed animals. This finding provides supportive evidence that irradiation of parents is an important factor in predisposition of progeny to chromosomal instability.