Embryo survival and fetal and placental growth following elevation of maternal estradiol blood concentrations in the rat

R.K. Bartholomeusz, Neville Bruce, Ann-Maree Lynch

    Research output: Contribution to journalArticlepeer-review

    34 Citations (Scopus)

    Abstract

    High doses of estrogens cause embryonic mortality, and fetal and placental growth retardation in rats. This study addresses the physiological relevance of such findings. Estradiol benzoate (EB), by s.c. injection, or estradiol-17 beta (E-2), delivered by a miniosmotic pump, raised maternal E-2 concentrations from only slightly above control values to 5-fold. EB (1 mu g/day) over Days 6-13, 8-13, and 11-13, and continuous infusion of E-2 (15 ng/h; Days 10-13) reduced fetal survival to 0%, 0%, 22%, and 75%, respectively. Single injections of EB showed that its lethal effect declined rapidly over Days 9 (44% survival) to 13 (90% survival). Embryos died within 48 h, but death was not due to luteal failure since progesterone levels were maintained and progesterone administered with EB did not reduce mortality. Administration of EB at 1 mu g/day (Dap 14-21) or E-2 at 40 ng/h (Days 13-16) retarded fetal and placental growth but did not affect survival. The rat embryo is highly sensitive to elevated maternal estradiol concentrations over much of gestation. The early lethal effect implies that endogenous E-2 production is carefully regulated to maintain pregnancy; the latter growth-retarding effect suggests that E-2 may have a role in the normal control of fetal growth.
    Original languageEnglish
    Pages (from-to)46-50
    JournalBiology of Reproduction
    Volume61
    DOIs
    Publication statusPublished - 1999

    Fingerprint

    Dive into the research topics of 'Embryo survival and fetal and placental growth following elevation of maternal estradiol blood concentrations in the rat'. Together they form a unique fingerprint.

    Cite this