Effect of fetal x‐irradiation upon the subsequent fertility of the offspring

Abstract

EIGHT FIGURESAdult male mice can tolerate rather high levels of x-irradiation to the testes before sterilization is brought on (Snell, '33 ; Hertwig, '38 ; Fogg and Cowling, '51 ; '52 ; Patt, '54 ; Nebel et al., '58)' but adult female mice may be sterilized with 100 r by 8 weeks or with 20 r by 36 weeks after a single exposure, or by chronic exposures of 10 r/week for a longer period (Rugh, '54, '56). Even radioiodine, reaching the suckling newborn through the mother's milk selectively sterilizes the female young (Rugh, '53), so that it is clearly demonstrated that the postnatal female mouse is more easily sterilized by ionizing radiations than is its litter mate male. It has been presumed that the fetus as a whole or any of its organ systems is more radiosensitive than is the adult or any of its organs. I t was therefore presumed that the gonad primordia, or the differentiating gonad of the mouse, would be more radiosensitive than the adult gonad, and that the ovary might be extremely sensitive, since the adult ovary could be sterilized by as little as 20 r. A preliminary study (Eugh, '52) with rather high levels of exposure (300 r accumulated in 6 exposures of 50 r each from gestation days 14-19> showed that sterility was imposed on both sexes among the offspring, but to a higher degree among males than females. This was the reverse of the adult response. Based on work performed under Contract AT-30-1-GEN-70 for The Atomic Energy Commission.

Radiosensitivity of Oogonia and Oocytes in the Foetal Rat

“…Rugh and Jackson's (1958) observations indicate that changes also occur in the radiosensitivity of the mouse ovary during late foetal life. Pregnant mice were irradiated between 15.5 and 18.5 days after insemination, and the reproductive capacity of the offspring was recorded from the 3rd to the 9th month after birth.…”

“…The radiosensitivity of the testis varies during the course of foetal development in both the rat and the mouse (Lengerov~ and Vojti~kov~ 1957, Rugh and Jackson 1958, Ershoff 1959, Beaumont 1960. Rugh and Jackson's (1958) observations indicate that changes also occur in the radiosensitivity of the mouse ovary during late foetal life.…”

Three methods for producing fertile hemopoietic chimeras in mice

“…A temporal "window" has been described between days 15.5 and 18.5 of gestation, at which time female mouse fetuses are more radioresistant than at any other time prior to or after birth (Rugh and Jackson, 1958). This was not attempted in the present study.…”

Effects of ionizing radiations on mammalian oogenesis: a model for chemical effects

“…In terms of reproductive capacity, a dose of 100 R reduced the number of pups produced by mice who had been prenatally exposed to x-rays to about half the number found in unirradiated sibs (23). The greatest reduction in reproductive capacity occurred in animals exposed on day 13.5 pc, when most of the germ cells were oogonia.…”