Selective Sterilization of Young Female Mice by Radioiodine Transmitted Through the Mother's Milk

Abstract

Summary and Conclusions

1. Ovaries of young newborn mice are very sensitive to ionizing radiations from radioiodine administered to the mother and reaching the young through the milk. The testes of litter mate male mice are very radioresistant under the same conditions. 2. A single injection of a nursing mouse with 600 μc of I¹³¹ reduced fertility in the female offspring by four months and made all female offspring sterile by 10 months while controls were 86% fertile. Litter mate males were never reduced to less than 75% fertility. 3. It appears that the ovary of 5-day-old mice is more sensitive to ionizing radiations from radioiodine than is the ovary of the 15-day-old mouse. 4. Even though exposure of the ovary of the young mouse to ionizing radiations was relatively brief, sterility was not evident for at least 4 months. Not only was the overall fertility of the female reduced, but so also was the length of the reproductive life span.