Concomitant mutagenicity of ethanol and x-ray irradiation in the mouse male germ cells

The mutagenic effect of ethanol and x-ray irradiation on the male germ cells was investigated in the mouse. The meiotic micronuclei in the testis were recorded and the abnormalities in the epididymal sperm heads were counted. The number of micronuclei in early spermatids did not differ in the ethanol-exposed groups from that of their control groups at the end of 5 week ethanol diets. However, in the mice irradiated with a dose of 0.5 Gy, there was a statistically significant (p less than 0.01) difference in micronucleus induction between the groups of different ethanol exposure levels. No statistically significant differences were found in the numbers of abnormal sperm heads immediately after the diet or 25 days, 5 weeks and 10 weeks after the cessation of the diet. However, sperm abnormality frequencies were elevated at 5 weeks after 4 and 6% (v/v) ethanol diets and at 25 days after the 6% diet. The results suggest that ethanol is co-mutagenic with x-rays in the mouse male germ cells. Ethanol alone showed also a tendency to be mutagenic in the sperm abnormality test. The stage and mechanism of action of ethanol is discussed.