Search results for "Promegestone"
showing 4 items of 4 documents
3H-estradiol and3H-R5020 binding in cytosols of normal and neoplastic human ovarian tissue
1983
High-affinity cytoplasmic estrogen and progesterone receptors in normal and abnormal ovarian tissues were studied. Estradiol receptor was detectable in 65% and progesterone receptor in 36% of the malignant tumors; 39% of all malignant ovarian tissues were estradiol- as well as progesterone-receptor-positive. Tumors were said to be receptor-positive when the receptors bound greater than 5 fM steroid/mg cytosol protein. No correlations were found between receptor status and histopathological diagnosis. In normal ovarian tissues collected at various phases of the menstrual cycle no changes in [3H]-estradiol and [3H]-R5020 binding could be detected. Analysis of the receptor concentration for bo…
A comparison of cytoplasmic and nuclear estradiol and progesterone receptors in human fallopian tube and endometrial tissue
1981
Quantitative and qualitative aspects of the in vitro binding of 3 H-estradiol and 3 H-progesterone to receptor components from human endometrium and fallopian tube cytoplasmic and nuclear fractions were studied. The steroid binding macromolecules formed in vitro could be extracted from nuclei by 0.4M KCl and detected by glycerol gradient centrifugation. Both estradiol- and progesterone-binding compounds formed only one peak (under high ionic strength conditions) with a sedimentation coefficient of about 4-5S. The number of cytoplasmic and nuclear binding sites for both estradiol and R5020 varied dramatically throughout the menstrual cycle: the estradiol and progesterone receptor concentrati…
3H-cyproterone acetate: binding characteristics to human uterine progestagen receptors
1985
The availability of tritium labeled cyproterone acetate (CPA) facilitated the systematic investigation of the binding characteristics of this compound for human uterine progesterone receptors (PgR). The binding parameters of 3H-CPA are compared to those of 3H-R5020 and 3H-progesterone. The rate constants of association (k1M-1sec-1) to PgR were 7.8 X 10(3) for 3H-R5020, 4.5 X 10(4) for 3H-progesterone and 4.0 X 10(4) for 3H-CPA. The rate constants of dissociation (k-1, sec-1) were 3.6 X 10(-5) for 3H-R5020, 21.3 X 10(-5) for 3H-progesterone and 17.8 X 10(-5) for 3H-CPA. The Kd-values (M), as obtained by titration analysis and subsequent Scatchard plot analysis were 1.2 X 10(-9) for 3H-R5020,…
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.