X-ray sterilization of immature female rats

Journal Article · Sun Oct 01 04:00:00 EDT 1961 · Journal of Endocrinology

DOI:https://doi.org/10.1677/joe.0.0230179· OSTI ID:4751032

MANDL, A. M.; ZUCKERMAN, S.

Ovaries of female weanling rats 18 to 29 days old were irradiated with 2200, 3150, or 4400 r. Judged by the absence of germ cells. direct irradiation of ovaries with 3150 and 4400 r leads to sterilization. Sterilization was often incomplete following exposure to 2200 r. some oocytes remaining. The age at which the vagina opened was about the same in animais steriiized at the age of 21 to 29 days as in their litter-mate controls. The rupture of the vaginal closure membrane was somewhat delayed in animals exposed to 4400 r at 18 to 20 days, and in unilaterally ovariectomized animais exposed to 4400 r at 23 to 26 days. Complete atrophy of the uterus did not occur within the experimental period of 12 weeks. The degree of involution corresponded to that of the ovaries. Changes in body weight and the weight of the pituitary and thymus were similar to those observed in adult rats following x-ray sterilization. Treatment with gonadotropins immediately after x irradiation (at the age of 19 to 24 days) led to a less rapid breakdown of the vaginal closure membrane n rats exposed to 4400 r than in either similarly treated litter-mates exposed to 3150 r or their nonirradiated controls. Treatment with gonadotropins during the 5 days preceding x irradiation (at the age of 23 to 28 days) was followed by an increase in subsequent secretion of estrogen, as judged by the pattern of vaginal smears and the weight of the uterus. The results indicate that x-ray sterilization leads to a more rapid cessation of ovarian secretion when carried out before than after the normal time of puberty, and that induction of precocious puberty by treatment with exogenous gonadotropins before but not after exposure to a sterilizing dose of x rays is associated with prolongation of the secretory capacity of the ovary. Whereas the ovaries of immature rats are capable of responding to gonadotropins immediately after exposure to 3150 r, the response is severely impaired 4 days after exposure to 4400 r. The difference between the 2 groups is probably due to the fact that a few follicles suvived treatment with 3150 r, at least during the first few days after irradiation, whereas exposure to 4400 r was followed by a rapid elimination of all follicles. The finding or regressing corpora lutea in many of the ovaries treated with 3150 r lends support to this view. An alternative, though less likely, hypothesis is that the damage to interstitial cells was more severe in the animals given the higher dose of x rays and treated with gonadotropins after a delay of 4 days.

• Research Organization: Univ. of Birmingham, Eng.
• Sponsoring Organization: USDOE
• NSA Number: NSA-17-005838
• OSTI ID: 4751032
• Journal Information: Journal of Endocrinology, Journal Name: Journal of Endocrinology Journal Issue: 2 Vol. 23; ISSN 0022-0795
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
AGE
ANIMAL CELLS
BODY
ESTROGENS
GLANDS
GONADOTROPINS
GONADS
HORMONES
PITUITARY GLAND
RADIATION DOSES
RADIATION EFFECTS
RADIOSENSITIVITY
RATS
SEX
STEROIDS
THYMUS
WEIGHT
X RADIATION