Detail of "1169-79-5"

Reference

Biology and receptor interactions of estriol and estriol derivatives in vitro and in vivo

Biology and receptor interactions of estriol and estriol derivatives in vitro and in vivo. Katzenellenbogen, Benita S. (Dep. Physiol. Biophys., Univ. Illinois, Urbana, IL 61801, USA). J. Steroid Biochem., 20(4B), 1033-7 (English) 1984. CODEN: JSTBBK. ISSN: 0022-4731. DOCUMENT TYPE: Journal CA Section: 2 (Mammalian Hormones) The biol. effects of estriol (E3) [50-27-1] were studied in 3 estrogen targets: the rat uterus in vivo and in vitro, in primary human endometrial cell cultures, and in MCF-7 human breast cancer cells in culture. Studies on the temporal relations between estrogen receptor binding and biol. responses in the uterus using E3 and several more long-acting E3 derivs.: 17a-ethynylestriol [4717-40-2], estriol-3-cyclopentyl ether [1169-79-5], and 17a-ethynylestriol-3-cyclopentyl ether [39791-20-3], indicate that E3 is a short-acting compd. with a brief duration of action. E3 is a poor stimulator of uterine growth and plasminogen activator activity in vivo. Chem. modifications of the E3 mol. produce long-acting derivs. that result in a prolonged input of hormone receptor complexes into the nucleus and a prolonged and marked stimulation of uterine growth. In human endometrial cells in primary tissue culture, E3 has 12% the affinity of estradiol (E2) [50-28-2] for cytosol estrogen receptor and it is quite effective yet slightly less potent than E2 in stimulation of progesterone receptor synthesis. Low concns. of E3 (10-10 M) stimulate growth of MCF-7 cells in vitro and dose-response curves show E3 to be only slightly less effective than E2. In these endometrial and breast cancer cell systems in vitro, there is no metab. of E3 but E2 is metabolized to estrone. Hence, E3 is an effective estrogen in vitro. In vivo, it is short-acting, but it can be made a full estrogen agonist when given at a sufficiently high concn. or in a chem. modified form which prolongs its activity by enabling effective concns. of the compd. to be maintained in the blood and in target tissues.