Lipoprotein cholesterol (C) supports the high rate of progesterone production by the human placenta as endogenous cholesterol synthesis is low. To study underlying mechanisms whereby lipoproteins, including high density lipoprotein-2 (HDL2), stimulate progesterone secretion, trophoblast cells were isolated from human term placentas and maintained in primary tissue culture. Lipoproteins were add...

What is EllaOne? EllaOne contains 30 mg ulipristal acetate (UPA), a synthetic selective progesterone receptor modulator, which has antagonistic and partial agonistic effects at the progesterone receptor level. Consequently, UPA should prevent the gene transcription normally activated by progesterone to produce the necessary proteins to support pregnancy. Over the last 10 years, other progestero...

Studies of the biological incorporation of isotopically labeled acetate into steroid hormones have become a well established tool in the field of steroid biochemistry. We have undertaken the study of the incorporation of acetate-l-U4 into the various sterols and steroid hormones of the pregnant mare. This study has been a joint undertaking of the two laboratories and has been the subject of sev...

Although the role of acetate as a substrate for steroid biosynthesis in systems in vitro is now well established (l-4), the role of mevalonate is currently somewhat obscure. A number of conflicting reports on the utilization of the latter substance for steroidogenesis have appeared in the literature. The diversity of steroidogenic tissue preparations that have been tested for their ability to u...

In vitro responsiveness of endometrial adenocarcinoma to progestins was evaluated histologically by incubation of tissue fragments in medium containing 10(-6) M medroxyprogesterone acetate. In a series of 19 experiments, formation of sub- and supranuclear vacuoles, which reflects accumulation of glycogen in response to medroxyprogesterone acetate added to the medium, was observed in well-preser...

In vitro responsiveness of endometrial adenocarcinoma to progestins was evaluated histologically by incubation of tissue fragments in medium containing 10~6 M medroxyprogesterone acetate. In a series of 19 experiments, formation of suband supranuclear vacuoles, which reflects accumulation of glycogen in re sponse to medroxyprogesterone acetate added to the medium, was observed in well-preserved...

gonad. Please refer to our general review". In the past studies on the biosyn thesis, emphasis was laid on the elucidation of production route of sex hormones . The route established to date runs thus : Acetate• ̈cholesterol-, 22-hydroxy cholesterol pregnenolone • ̈ progesterone • ̈17-hydroxy progesterone-• ̈ƒ¢4-and rostene-3, 17-dione• ̈19-hydroxy-ƒ¢4-and rostenedione-,estrone->estradiol-17ƒÀ , but...

1. Ovariectomy-delayed blastocysts flushed from mice treated with medroxyprogesterone acetate were injected into the lumina of immature mouse uterine horns. The horns were then maintained as organ cultures for 1-3 days in media that contained either (a) ethanol or ethanol plus (6) progesterone, (c) oestradiol or (d) progesterone and oestradiol. 2. Trophoblast invasion of the uterine stroma occu...

In the last two decades the prevailing opinion, supported by the "estrogen augmented by progesterone" hypothesis, has been that progesterone contributes to the development of breast cancer (BC). Support for this opinion was provided by the finding that some synthetic progestins, when added to estrogen in hormone replacement therapy (HRT) for menopausal complaints, increase the BC risk more than...