Progesterone receptor immunoreactivity at the maternofetal interface of first trimester pregnancy: a study of the trophoblast population

The aim of our study was to localize oestrogen receptor (ER) and progesterone receptor (PR) in the trophoblast population at the maternofetal interface in early pregnancy. Rat monoclonal antibodies to human ER and PR were used to study 44 cases of chorionic villi and 82 cases of decidua using an immunocytochemical method. The PR-immunoreactive products were localized in the nuclei of syncytiotrophoblast and cytotrophoblast cells of the villi. Specific staining was also present in the cytoplasm. Villous stroma and vessels were stained occasionally. Using cytokeratin staining in an adjacent section or double staining with PR and cytokeratin, the distribution of invading trophoblast cells and their PR expression were examined. In decidual stroma, a type of interstitial cell was identified which simultaneously expressed cytokeratin and PR in the cytoplasm, indicating that the invading trophoblast cells may express PR. All extravillous populations at the interface were positive for PR, including the syncytial lining of the decidual surface, the cytotrophoblast column, the cytotrophoblast shell and the interstitial trophoblast. The immunoreactivity of PR was also localized in the nuclei of vascular endothelial cells, whereas Factor VIII was localized in the cytoplasm of the same cells, thus confirming their endothelial nature. In contrast to PR, little ER could be detected in the trophoblast cell population using anti-ER antibody D75 in our study.

Early changes of affinity and binding sites of progesterone and oestrogen receptors in decidua exposed to RU 486

Sixty patients with 6-7 weeks of amenorrhoea were randomly allocated to three groups. The women in the first group (control) took a placebo 24 h before undergoing a vacuum aspiration. The patients in the second and third groups were given 200 mg of RU 486 orally, 12 or 24 h before surgical interruption of their pregnancy. Decidua were collected and frozen in liquid nitrogen. By Scatchard plot analysis, the number of cytosolic binding sites (1798 +/- 803 fmol/mg DNA) of progesterone in decidua in the control group was significantly reduced (P less than 0.01) to 696 +/- 408 or 626 +/- 179 fmol/mg DNA by RU 486 treatment for 12 or 24 h respectively. The dissociation constants of both cytosolic and nuclear progesterone receptors in RU 486-exposed decidua were increased (P less than 0.01). The number of nuclear binding sites of oestrogen receptor was significantly higher (P less than 0.05) in decidua with RU 486 treatment for 12 h (178 +/- 77 fmol/mg DNA) compared to the control (89 +/- 32 fmol/mg DNA). The results suggest that RU 486 might regulate progesterone and oestrogen receptors in the decidua of early human pregnancy, either directly or indirectly.

Immunohistochemical localization of progesterone receptor in human decidua of early pregnancy

Rat monoclonal antibodies to human progesterone receptor were used for immunolocalization studies in human decidua of early pregnancy. Frozen sections of 42 specimens of decidua were stained by the peroxidase-antiperoxidase method (PAP). Progesterone receptor was localized exclusively in the nuclei of decidual and myometrial cells with no specific staining in the cytoplasm. In the decidualized endometrium, stroma were always positively stained. Smooth muscle, pericyte and endothelial cells of blood vessels were extensively stained. Glandular epithelia showed variation in staining, which was positive in the basal but very weak or negative in the superficial layer of the decidua. No specific staining could be detected in the control sections. Of special interest was the positive staining of the endothelium of decidual blood vessels, a finding which has not been reported previously. The cells of the inner lining of vessels that stained with the antiprogesterone receptor antibodies were also Factor VIII positive, thus confirming the endothelial nature of these cells. It is concluded from these results that endothelial cells from human first trimester decidua express progesterone receptors.

Pregnancy interruption with RU 486 in combination with dl-15-methyl-prostaglandin-F2 alpha-methyl ester: the Chinese experience

In a multicenter study taking place in four centers in Beijing (People's Republic of China), pregnancies up to 49 days of amenorrhea (DA) were interrupted with RU 486 (RU 38486, mifepristone, 600 mg orally once), followed 36-60 hours later by administration of dl-15-methyl-PGF 2 alpha-methyl ester (PG05, 1 mg vaginal suppository). One-hundred-and-sixty women were included in the study, three of whom being excluded from efficacy assessment because of non-compliance to the protocol. Complete pregnancy interruption without additional surgical procedure (success) was obtained in 136 women (86.6%, 95% confidence interval: 81.3-91.9%). The success rate was significantly (P = 0.013) higher for pregnancies below (91.3%), than for pregnancies above 42 days of amenorrhea (DA) (76.6%). The time elapsed between RU 486 intake and complete expulsion was 2.8 +/- 1.5 (sd) days (range: 1-12 days). Expulsion took place at the latest 4 days after RU 486 in 125 women (94.7%), and in 107 of these women, it occurred 3.1 +/- 1.7 (sd) hours after PG05 administration. Uterine bleeding occurred in all women after RU 486 intake whatever the outcome of treatment and lasted 11.5 +/- 4.8 (sd) days (range: 3-36 days). It was judged more or much more abundant than usual periods in 6.15% of the women. It led to a slight but significant decrease in hemoglobin as measured eight and 14 days after RU 486 intake. In five women, hemoglobin decreased by 4 g/dl or more, but no patient required a blood transfusion.(ABSTRACT TRUNCATED AT 250 WORDS)