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Title: Progesterone and estradiol plasma levels in neonatally irradiated cycling rats

Female rats which were exposed to a single low dose of gamma irradiation (6R or 15R) at the age of 8 days produce smaller litters when mature than untreated controls. The possibility that the impaired fertility resulted from altered ovarian activity as reflected by changes in plasma levels of progesterone or estardiol was investigated. Plasma levels of both steroids were determined throughout the day of proestrus. Progesterone level was also determined in 6R animals on the day of weaning. The maturity of such irradiated rats was assessed by observing the time of vaginal opening. The results indicated that the preovulatory peak of progesterone was delayed in the 6R rats whereas in the 15R group its levels were significantly lower. On the other hand no differences in estradiol plasma levels were noticed between the groups. The higher level of progesterone in the 6R animals was not evident on the day of weaning and was even in both groups, but vaginal opening in the irradiated rats was significantly delayed. The elevated level of progesterone might be responsible, among other endocrine changes, for the lower fertility of neonatally irradiated mature female rats.
Authors:
;  [1]
  1. (Nuclear Research Center-Negev, Beer-Sheva (Israel))
Publication Date:
OSTI Identifier:
7062127
Resource Type:
Journal Article
Resource Relation:
Journal Name: Endocrine Research; (USA); Journal Volume: 16:2
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; ESTRADIOL; BIOSYNTHESIS; GAMMA RADIATION; TERATOGENESIS; PROGESTERONE; ACUTE IRRADIATION; ESTROUS CYCLE; FEMALES; FERTILITY; LOW DOSE IRRADIATION; NEONATES; OVARIES; RATS; WHOLE-BODY IRRADIATION; ACUTE EXPOSURE; ANIMALS; BODY; ELECTROMAGNETIC RADIATION; ESTRANES; ESTROGENS; EXTERNAL IRRADIATION; FEMALE GENITALS; GONADS; HORMONES; HYDROXY COMPOUNDS; IONIZING RADIATIONS; IRRADIATION; KETONES; MAMMALS; ORGANIC COMPOUNDS; ORGANS; PREGNANES; RADIATIONS; RODENTS; STEROID HORMONES; STEROIDS; SYNTHESIS; VERTEBRATES 560152* -- Radiation Effects on Animals-- Animals