will be down for maintenance on 16 May, 2022 from 18:00-22:00 Pacific US. We apologize for any inconvenience.
Translator Disclaimer
1 July 2004 Progesterone and Placental Hormone Actions on the Uterus: Insights from Domestic Animals
Thomas E. Spencer, Greg A. Johnson, Robert C. Burghardt, Fuller W. Bazer
Author Affiliations +

Progesterone is unequivocally required for maternal support of conceptus (embryo/fetus and associated extraembryonic membranes) survival and development. In cyclic sheep, progesterone is paradoxically involved in suppressing and then initiating development of the endometrial luteolytic mechanism. In cyclic and pregnant sheep, progesterone negatively autoregulates progesterone receptor (PR) gene expression in the endometrial luminal (LE) and superficial glandular epithelium (GE). In cyclic sheep, PR loss is closely followed by increases in epithelial estrogen receptor (ERα) and then oxytocin receptor (OTR), allowing oxytocin to induce uterine release of luteolytic prostaglandin F2α pulses. In pregnant sheep, the conceptus produces interferon tau (IFNτ) that acts on the endometrium to inhibit transcription of the ERα gene and thus development of the endometrial luteolytic mechanism. After Day 13 of pregnancy, the endometrial epithelia do not express the PR, whereas the stroma and myometrium remain PR positive. The absence of PR in the endometrial GE is required for onset of differentiated function of the glands during pregnancy. The sequential, overlapping actions of progesterone, IFNτ, placental lactogen (PL), and growth hormone (GH) comprise a hormonal servomechanism that regulates endometrial gland morphogenesis and terminal differentiated function during gestation. In pigs, estrogen, the pregnancy-recognition signal, increases fibroblast growth factor 7 (FGF-7) expression in the endometrial LE that, in turn, stimulates proliferation and differentiated functions of the trophectoderm, which expresses the receptor for FGF-7. Strategic manipulation of these physiological mechanisms may offer therapeutic schemes to improve uterine capacity, conceptus survival, and reproductive health of domestic animals and humans.

Thomas E. Spencer, Greg A. Johnson, Robert C. Burghardt, and Fuller W. Bazer "Progesterone and Placental Hormone Actions on the Uterus: Insights from Domestic Animals," Biology of Reproduction 71(1), 2-10, (1 July 2004).
Received: 7 October 2003; Accepted: 1 November 2003; Published: 1 July 2004

mechanisms of hormone action
Get copyright permission
Back to Top