The Effect on the Sensitivity of the Mouse Testis of Different Oxygen Tensions during Irradiation

Summary

The OER for mouse testis weight-loss after irradiation has been obtained for both the sensitive component of weight-loss (1·8) and the insensitive component (2·5). The regression lines fitted to the high-dose data for animals breathing oxygen or nitrogen during irradiation extrapolate to the same value at zero dose, indicating that the cells responsible for the insensitive component form a fixed proportion of the population that is independent of oxygen-tension. The weight-loss in animals breathing 8 per cent oxygen during irradiation was the same as in animals breathing air. Breathing oxygen at 3 atmospheres pressure does not increase the sensitivity of either component of testis weight-loss and may decrease the insensitive component.