antiprogestin

antiprogestin

 [an″te-, an″ti-pro-jes´tin]
a substance that inhibits the formation of progestational agents; the most common example is mifepristone.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

an·ti·pro·ges·tin

(an'tē-prō-jes'tin),
A substance that inhibits progesterone formation, that interferes with its carriage or stability in the blood, or that reduces its uptake by, or effects on, target organs (for example, RU486, mifepristone).
Farlex Partner Medical Dictionary © Farlex 2012

an·ti·pro·ges·tin

(an'tē-prō-jes'tin)
A substance that inhibits progesterone formation, interferes with its carriage or stability in the blood, or reduces its uptake by, or effects on, target organs (e.g., RU-486, mifepristone).
Synonym(s): progesterone antagonist.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
Double-blind phase III randomized trial of the antiprogestin agent mifepristone in the treatment of unresectable meningioma: SWOG S9005.
Studies have also shown that the combination of triptorelin and related receptors is 120 to 180 times that of native GnRH, and its activity is 30 to 50 times.21 Gestrinone is a 19-nortestosterone steroidal drug with antiprogestin, moderate antiestrogens and resistant gland effects, which increases free testosterone levels, reduces sex hormone binding protein levels, inhibits FSH, LH peaks and reduces LH The mean value causes the estrogen level in the body to decrease, and the ectopic endometrium shrinks and absorbs.
Since ulipristal is an antiprogestin; there are implications on starting progestin-containing hormonal contraceptives immediately after taking it.
The drugs used were mainly mifepristone (RU 486), a potent antiprogestin in combination with prostaglandin [E.sub.1] analogue misoprostol.
By the way, the relevance of progesterone, alone or together with estrogens, as the main factors regulating hippocampal ability to store and retrieve memory is supported by the increased risk to develop Alzheimer's disease in postmenopausal women [62, 63] and by the observation that the antiprogestin RU486 administration on proestrus blocks the natural decline of synapse density related to cycle [64].
When bound by the antiprogestin RU486 the progesterone receptor begins a series of events ending in the increase of Kruppel-like factor 11 (KLF11).
Leukocyte populations and steroid receptor expression in human first-trimester decidua; regulation by antiprogestin and prostaglandin E analog.
There are three types of ECPs: combined ECPs containing both estrogen and progestin, progestin-only ECPs, and ECPs containing an antiprogestin (either mifepristone or ulipristal acetate).
Mifepristone is an antiprogestin licensed for pregnancy termination in more than 40 countries around the world.
Exposure of BT-474 cells to MPA in vitro also resulted in lower levels of RANKL; an effect that was independent of progesterone receptors since it occurred both in the presence and absence of the antiprogestin RU-486.