Mouse dominant lethal and sperm abnormality studies with combined exposure to X-rays and mitomycin C

The induction of dominant lethal effects and sperm abnormalities in Pzh:Swiss male mice after treatments with X-rays and mitomycin C (MMC) was investigated. Combinations of high (1.00 Gy + 5.25 mg/kg bw MMC) and low (0.25 Gy + 1.75 mg/kg bw MMC) doses of both agents were used. Exposure to high doses of X-rays + MMC induced an increased rate of dominant lethal mutations in spermatogonia and late spermatocytes. Combined treatment with low doses of X-rays and MMC was not mutagenic in any stage of spermatogenesis. MMC increased the frequency of abnormal spermatozoa after exposure alone and in combination with X-rays. Treatment with two high doses (1.00 Gy + 5.25 mg/kg bw MMC) induced 58.4% abnormal spermatozoa. After combined exposure to low doses of both agents 35.7% spermatozoa with malformations were observed.