Biomaterial Database

Progesterone "receptor" in rat ovary. 1979

J R Schreiber, and J W Hsueh

A soluble thermolabile protein with many characteristics of a progesterone receptor has been identified in ovaries of estrogen-stimulated, hypophysectomized, immature female rats. A potent synthetic progestin R5020 (17,21-dimethyl-19-nor-pregna-4, 9-diene-3, 20-dione) and a progestin-receptor complex stabilizer (glycerol) were employed. After the incubation of [3H]R5020 with ovarian cytosol, fractionation of a Sephadex G-200 column revealed a peak of radioactivity which eluted with the void volume. This peak, which represented saturable binding, disappeared after heating (37 C for 20 min) and trypsinization. In the absence of glycerol, binding decreased by 84%. Scatchard analysis of the binding curve showed the R5020 binding to be of moderately high affinity (Kd 4 nM), with 232 fmol binding sites/mg cytosol protein. Binding site number rose linearly with increasing cytosol protein concentration. The relative abilities of various steroids to inhibit [3H]R5020 Binding were: R5020 greater than progesterone greater than estradiol greater than testosterone greater than cortisol greater than diethylstilbestrol. [3H]R5020 was not metabolized and did not bind specifically to serum. In summary, we have identified a protein with characteristics of a progesterone receptor in the cytoplasmic fraction of ovarian tissue.

UI	MeSH Term	Description	Entries
D007016	Hypophysectomy	Surgical removal or destruction of the hypophysis, or pituitary gland. (Dorland, 28th ed)	Hypophysectomies
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010053	Ovary	The reproductive organ (GONADS) in female animals. In vertebrates, the ovary contains two functional parts: the OVARIAN FOLLICLE for the production of female germ cells (OOGENESIS); and the endocrine cells (GRANULOSA CELLS; THECA CELLS; and LUTEAL CELLS) for the production of ESTROGENS and PROGESTERONE.	Ovaries
D011397	Promegestone	A synthetic progestin which is useful for the study of progestin distribution and progestin tissue receptors, as it is not bound by transcortin and binds to progesterone receptors with a higher association constant than progesterone.	17,21-Dimethyl-19-nor-4,9-pregnadiene-3,20-dione,Promestone,R-5020,R5020,RU-5020,RU5020,Surgestone,R 5020,RU 5020
D011980	Receptors, Progesterone	Specific proteins found in or on cells of progesterone target tissues that specifically combine with progesterone. The cytosol progesterone-receptor complex then associates with the nucleic acids to initiate protein synthesis. There are two kinds of progesterone receptors, A and B. Both are induced by estrogen and have short half-lives.	Progesterone Receptors,Progestin Receptor,Progestin Receptors,Receptor, Progesterone,Receptors, Progestin,Progesterone Receptor,Receptor, Progestin
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
D004054	Diethylstilbestrol	A synthetic nonsteroidal estrogen used in the treatment of menopausal and postmenopausal disorders. It was also used formerly as a growth promoter in animals. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), diethylstilbestrol has been listed as a known carcinogen. (Merck, 11th ed)	Stilbestrol,Agostilben,Apstil,Diethylstilbestrol, (Z)-Isomer,Diethylstilbestrol, Disodium Salt,Distilbène,Stilbene Estrogen,Tampovagan,Estrogen, Stilbene
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001667	Binding, Competitive	The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.	Competitive Binding