Search results for "Progesterone Congener"
showing 7 items of 7 documents
Synthesis of a New Disulfide Affinity Adsorbent for Purification of Human Uterine Progesterone Receptor
2005
For purification of the human uterine progesterone receptor, an affinity adsorbent was synthesized in which the specific ligand (16 alpha-ethyl-3-oxo-19nor-androst-4-ene 17 beta-carboxylic acid) was bound to derivatized celulose using a disulfide-group-containing spacer. The purified receptor protein, isolated by reductive cleavage of the disulfide bond, bound the synthetic gestagen R5020 with high affinity (Kd 12.2 nmol/l). The affinity gel was highly efficient. A 24000-fold purification of progesterone receptor with a recovery of 40% could be achieved in a single step within 6 h. By means of dodecyl sulphate/polyacrylamide gel electrophoresis two main polypeptides with molecular weights o…
Binding of oral contraceptive progestogens to serum proteins and cytoplasmic receptor
1990
Abstract Some progestogens widely used in oral contraceptives are characterized at the level of high-affinity receptor binding as well as binding to sex hormone-binding globulin and corticosteroid-binding globulin. With regard to binding to sex hormone-binding globulin, gestodene, levonorgestrel, and to a lesser extent 3-ketodesogestrel (which is only formed from the prodrug desogestrel in the body), show a behavior that is manifested in the relatively high affinity to sex hormone-binding globulin, whereas desogestrel and norgestimate do not display any measurable affinity for this specific steroid-binding serum protein. Furthermore, levonorgestrel and gestodene dissociate very much more sl…
Estradiol reduces F2α-isoprostane production in cultured human endothelial cells
2002
Free radical-generated F2α-isoprostanes are a group of compounds with vasoconstrictor properties. To investigate whether estradiol exerts antioxidant actions modifying F2α-isoprostane production, cultured human umbilical vein endothelial cells were exposed to estradiol and other compounds and F2α-isoprostanes were measured in culture medium. Exposure to 1 and 10 nM estradiol for 24 h reduced F2α-isoprostane production by 36 and 49%, respectively ( P < 0.001 vs. control). Exposure to antiestrogens alone (ICI-182780 or EM-652) slightly reduced F2α-isoprostanes ( P < 0.05 vs. control), but much less than exposure to estradiol ( P < 0.05). ICI-182780 reversed the estradiol-induced redu…
Long-term effects of oral and transdermal hormone replacement therapy on plasma homocysteine levels.
2003
Objective To compare the long-term effects of oral and transdermal hormone replacement therapy (HRT) on serum homocysteine levels in postmenopausal women. Design An open, prospective, controlled study. Seventy-five healthy postmenopausal women were recruited as eligible for the study. Fifty women seeking HRT were randomized to receive continuous 17beta-estradiol, either by oral (2 mg daily; n = 25) or transdermal (50 microg daily; n = 25) administration, plus 10 mg dydrogesterone daily for 14 days of each 28-day cycle. Twenty-five women unwilling to receive hormone treatment received only calcium supplementation, representing the control group. Fasting blood samples were analyzed at baselin…
Biotin-Labelled and Photoactivatable Aldosterone and Progesterone Derivatives as Ligands for Affinity Chromatography, Fluorescence Immunoassays and P…
1996
New derivatives of progesterone and aldosterone were synthesized and functionally tested with commercially available antibodies. The covalent labelling of antibodies specific for aldosterone and progesterone was detected by SDS/PAGE analysis and subsequent autoradiography after using 3-(O-carboxymethyl)-oximino-(3-[125I]iodo-4-azidosalicylamidobu tylamine) derivatives of aldosterone and progesterone, respectively, as photoactivatable radioligands. Labelling was not observed in the presence of an excess of the unlabelled steroid. Aldosterone was labelled with biotin and used as a tracer in a time-resolved fluorescence immunoassay. The nonradioactive tracer is highly selective for its antibod…
Lack of binding of gestodene to estrogen receptor in human breast cancer tissue
1990
Competition studies with progesterone and estradiol receptors of human myometrial tissue as well as of mammary cancer tissue showed that gestodene bound with high affinity to the progesterone receptor, as did other synthetic and natural progestogens. However, gestodene did not bind to the estradiol receptor. The relative binding affinities of all tested synthetic and natural ligands showed no organ-specific differences and no differences between neoplastically transformed and normal tissues.
Two-year prospective, randomized trial comparing an innovative twice-a-week progestin regimen with a continuous combined regimen as postmenopausal ho…
1999
Abstract Objective: To compare compliance, symptom control, bleeding patterns, endometrial response, and lipid changes in postmenopausal women treated with transdermal E 2 and a regimen of either intermittent or continuous dosing of progestin. Design: Randomized, prospective study. Setting: Menopausal Outpatient Clinic at an academic tertiary care hospital. Patient(s): One hundred women who had reached menopause naturally and had been amenorrheic for at least 1 year. Fifty women were randomly assigned to receive each regimen. Intervention(s): All patients received 50-μg E 2 patches and medroxyprogesterone acetate, either 5 mg twice per week or 2.5 mg daily. The bleeding pattern was register…