EFFECT OF IRRADIATION DURING FOETAL LIFE ON THE SUBSEQUENT STRUCTURE AND SECRETORY ACTIVITY OF THE GONADS

Abstract

SUMMARY Pregnant rats were exposed to 100r. acute X-irradiation at 13·5, 15·5, 17·5 and 19·5 days post coitum (p.c.). The offspring were killed 100 days after birth, and records were made of their body weight and the weights of the pituitary, adrenal glands, ovaries and uterus (or testes and accessory sex organs). The results of quantitative studies of the population of germ cells confirmed that radiosensitivity of the germinal elements of the female foetus is maximal at 15·5 days p.c. In contrast, the male germ cells become increasingly radiosensitive as pregnancy advances (17·5–19·5 days p.c.). Severe depopulation of oocytes appears to be associated with a slight decline in the secretory activity of the ovary. The endocrine function of the testis is not affected by exposure to 100r., a dose sufficient to cause almost complete elimination of germinal cells.