Quiescent full-grown Xenopus oocytes remain arrested at the G(2)/M border of meiosis I until exposed to progesterone, their natural mitogen. Progesterone triggers rapid, nontranscriptional responses that lead to the translational activation of stored mRNAs, resumption of the meiotic cell cycles, and maturation of the oocyte into a fertilizable egg. It has long been presumed that progesterone ac...

BACKGROUND The transport of gametes as well as the zygote is facilitated by motile cilia lining the inside of the fallopian tube. Progesterone reduces the ciliary beat frequency within 30 minutes in both cows and mice. This rapid reduction suggest the involvement of a non-genomic signaling mechanism, although it is not known which receptors that are involved. Here we investigated the possible i...

Childbearing and use of oral contraceptives are known to lower the risk of ovarian cancer, and it has been suggested that progesterone or progestin exposures play a role in these associations. The effects of progesterone may be mediated in part through the progesterone receptor, which exists in two functionally distinct protein isoforms, hPR-A and hPR-B. It is known that individuals carrying th...

Childbearing and use of oral contraceptives are known to lower the risk of ovarian cancer, and it has been suggested that progesterone or progestin exposures play a role in these associations. The effects of progesterone may be mediated in part through the progesterone receptor, which exists in two functionally distinct protein isoforms, hPR-A and hPR-B. It is known that individuals carrying th...

Women with inherited BRCA1 mutations have an elevated risk (40-80%) for developing breast and ovarian cancers. Reproductive history has been reported to alter this risk, suggesting a relationship between ovarian hormone signaling and BRCA1-related tumor development. BRCA1 interactions with estrogen receptor (ER) and progesterone receptor (PR) signaling were previously described in human breast ...

PURPOSE To assess a possible association between polymorphism of the progesterone receptor gene (PROGINS) and recurrent spontaneous abortion (RSA). METHODS In this case-control study, 85 women with at least three previous spontaneous abortions without an identifiable cause (RSA Group) and 157 women with at least two previous term pregnancies without pathologies and no previous miscarriage (Co...

The progesterone receptor (PGR) is a nuclear receptor transcription factor that is essential for female fertility, in part due to its control of oocyte release from the ovary, or ovulation. In all mammals studied to date, ovarian expression of PGR is restricted primarily to granulosa cells of follicles destined to ovulate. Granulosa cell expression of PGR is induced by the pituitary Luteinizing...

OBJECTIVE It is not known whether progesterone, which plays a key role in establishing and maintaining pregnancy, acts directly on embryos or indirectly through the mother's reproductive tract. Since the physiological effects of progesterone are mediated by progesterone receptors (PR), the expression of PR during the preimplantation stages of pig embryos was determined. DESIGN AND METHODS Pre...

Progesterone is critical to normal breast development, and its activity is mediated by the progesterone receptor (PR) that is part of the steroid-thyroid-retinoic acid receptor superfamily of transcription factors (1). A single copy of the progesterone receptor gene (PGR), located on chromosome 11q22-23, uses separate promoters and translation start sites to produce two protein isoforms, PR-A a...

Progesterone is critical to normal breast development, and its activity is mediated by the progesterone receptor (PR) that is part of the steroid-thyroid-retinoic acid receptor superfamily of transcription factors (1). A single copy of the progesterone receptor gene (PGR), located on chromosome 11q22-23, uses separate promoters and translation start sites to produce two protein isoforms, PR-A a...