Reference

The effect of low dose progestogens on hypothalamic-pituitary-ovarian function

The effect of low dose progestogens on hypothalamic-pituitary-ovarian function. Friedrich, E. (Med. Fak., Tech. Hochsch. Aachen, Aachen, Ger.). Fortschr. Med., 95(29), 1827-32 (German) 1977. CODEN: FMDZAR. DOCUMENT TYPE: Journal CA Section: 2 (Hormone Pharmacology) Lynestrenol [52-76-6] (0.5 mg/day) and ORG 3236 [54048-10-1] (0.025 or 0.05 mg/day) given to normal women as minipill contraceptives were very effective in decreasing the secretion of FSH [9002-68-0], LH [9002-67-9], progesterone [57-83-0], and 17.beta.-estradiol [50-28-2] at the middle of the ovarian cycle thereby accounting for their effectiveness.

Binding of progestagens to receptor proteins in MCF-7 cells

Binding of progestagens to receptor proteins in MCF-7 cells. Bergink, E. W.; Van Meel, F.; Turpijn, E. W.; Van der Vies, J. (Sci. Dev. Group, Organon Int. B.V., Oss, Neth.). J. Steroid Biochem., 19(5), 1563-70 (English) 1983. CODEN: JSTBBK. ISSN: 0022-4731. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) The specificity of progestogens currently used for contraceptive purposes for progesterone [57-83-0], androgen, and estrogen receptors was assessed in MCF-7 cells. 7358-46-5 and 595-33-5 which are cas registry numbers of chemicals are mentioned. The specificity of progestogens for the progesterone receptors in the cytosol fraction of MCF-7 cells was similar to that for progesterone receptors in human and rabbit myometrial cytosol but different from that for the progesterone receptor in rat myometrial cytosol. At 37° the relative affinity of 3-keto-desogestrel [54048-10-1], the major metabolite of desogestrel, for the progesterone receptor in intact MCF-7 cells was twice that of levonorgestrel [797-63-7] and ORG 2058 [24320-06-7], 3 times that of medroxyprogesterone acetate (MPA) [71-58-9], 4.5 times that of norethisterone [68-22-4], and 5 times that of progesterone and cyproterone acetate [427-51-0] whereas at 4° in the cytosol fraction of MCF-7 cells exposed to molybdate (nontransformed receptor complexes) 3-keto-desogestrel and Org 2058 displayed similar affinity. The stronger binding of 3-keto-desogestrel in intact cells was due to the higher stability of its complex with the progesterone receptor. At 37° the relative affinity of 3-keto-desogestrel for the androgen receptor in intact MCF-7 cells was half that of levonorgestrel, similar to that of norethisterone and MPA, and at least 3 times higher than that of progestogens with antiandrogenic activity whereas at 4° in the cytosol fraction exposed to molybdate there was no clear difference between the relative affinities of progestogens with androgenic and antiandrogenic properties. Of the progestogens tested, only norethinodrel [68-23-5] displayed measurable but very low relative affinity for the estrogen receptor in MCF-7 cells. The present results of binding studies with intact MCF-7 cells correlated better with the known hormonal properties of progestogens than those obtained with the cytosol fraction exposed to molybdate at 4°. .