Vascular changes in the human endometrium following the administration of the progesterone antagonist RU 486

Second Trimester Medical Abortion with Mifepristone–Misoprostol and Misoprostol Alone: A Review of Methods and Management

“…It prevents softening and dilatation of the cervix, reduces PG output from the decidua and suppresses uterine contractions. Thus, the blocking of progesterone receptors by mifepristone results in vascular damage, decidual necrosis and bleeding, 8,21 which leads to cervical softening, increased uterine sensitivity to PG and conversion of the quiet pregnant uterus into an organ of spontaneous activity with maximal effect at 36-48 hours. 8,9,22,23 Misoprostol is a synthetic PGE-1 analogue which induces cervical ripening as well as strong uterine contractions and leads to expulsion of a pregnancy.…”

Effect of early luteal phase administration of mifepristone (RU486) on leukaemia inhibitory factor, transforming growth factor beta and vascular endothelial growth factor in the implantation stage endometrium of the rhesus monkey

“…Therefore, the observed changes in the cytokines characterized by high LIF and TGF together with decreased VEGF in the vascular compartment are suggestive of a major functional change in this compartment. Previous morphological studies also revealed that small blood vessels were affected together with microhaematoma and enhanced emigration of leucocytic cells into the extracellular matrix in mid-luteal phase endometrium after mifepristone administration in human volunteers ( Johannisson et al 1989) and in monkeys (Ghosh et al 1996).…”

“…A single dose application of this anti-progestin agent on day 2 after ovulation can inhibit blastocyst implantation, with no notable changes in menstrual cyclicity in women and in monkeys (Gemzell-Danielsson et al 1993, Ghosh & Sengupta 1993. It has been shown that luteal phase administration of mifepristone to women and to monkeys induced desynchronization of endometrium, repressed glandular secretory differentiation and vascular maturation (Li et al 1988, Johannisson et al 1989, Gemzell-Danielsson et al 1994, Ghosh et al 1996. We have reported previously that administration of mifepristone on day 2 after ovulation results in differential profiles of secretory proteins (Ghosh et al 1997a).…”

Mifepristone-Exposured Human Endometrial Endothelial Cells In Vitro

“…[13][14][15] Johannisson et al observed significant changes in the endometrial vessels after mifepristone administration, seen as cell injury and cell death in capillary endothelial cells. 16 This vascular damage has been proposed to compromise the embryo survival. 17 Mifepristone has also been previously reported to affect the endometrial receptivity markers in a coculture system of human endometrial epithelial and stromal cells.…”