In women, endometrial morphology and function undergo characteristic changes every menstrual cycle. These changes are crucial for perpetuation of the species and are orchestrated to prepare the endometrium for implantation of a conceptus. In the absence of pregnancy, the human endometrium is sloughed off at menstruation over a period of a few days. Tissue repair, growth, angiogenesis, differentiation, and receptivity ensue to prepare the endometrium for implantation in the next cycle. Ovarian sex steroids through interaction with different cognate nuclear receptors regulate the expression of a cascade of local factors within the endometrium that act in an autocrine/paracrine and even intracrine manner. Such interactions initiate complex events within the endometrium that are crucial for implantation and, in the absence thereof, normal menstruation. A clearer understanding of regulation of normal endometrial function will provide an insight into causes of menstrual dysfunction such as menorrhagia (heavy menstrual bleeding) and dysmenorrhea (painful periods). The molecular pathways that precipitate these pathologies remain largely undefined. Future research efforts to provide greater insight into these pathways will lead to the development of novel drugs that would target identified aberrations in expression and/or of local uterine factors that are crucial for normal endometrial function.

/pdf/endocrine-regulation-of-menstruation-2jsj6iqvat.pdf

Endocrine regulation of menstruation.

RU 486, a steroid with high affinity for the progesterone receptor, is the first available active antiprogesterone. It has been used successfully as a medical alternative for early pregnancy interruption, and it also has other potential applications in medicine and for biochemical and pathophysiological endocrine research.

https://science.sciencemag.org/content/sci/245/4924/1351.full.pdf

Contragestion and other clinical applications of RU 486, an antiprogesterone at the receptor

Background:Arteriovenous malformation is a dynamic vascular anomaly; it expands with age and after treatment. This study analyzed the pattern of arteriovenous malformation progression and frequency of recurrence after therapy.Methods:Patients with cutaneous and soft-tissue arteriovenous malformation

Extracranial arteriovenous malformations: natural progression and recurrence after treatment.

The accuracy and reproducibility of the endometrial receptivity array is superior to histology as a diagnostic method for endometrial receptivity.

https://www.hormonebalance.org/images/documents/Vaginal%20Drug%20administation%20Alexander%20F&S%2004.pdf

Why consider vaginal drug administration

Endometrial morphology and peripheral hormone levels in women with regular menstrual cycles

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

Pharmacokinetic and Pharmacodynamic Effects of Small Doses of Norethisterone Released from Vaginal Rings Continuously During 90 Days

Endometrial biopsies from 90 women with regular menstrual cycles and a hormonal profile compatible with normal luteal function were morphometrically assessed using 11 different indices and the results were plotted in 48-hour periods around the day of the luteinizing hormone (LH) surge (LH +/- 0). The endometrial dating reached its highest significance from days LH -3/-2 to days LH +7/+8, when the changes occurred with a high degree of regularity regardless of the length of the preovulatory and postovulatory phases. It is proposed therefore that the dating of the endometrium should be related to the LH surge rather than to the "ideal" 28-day cycle. The results also seem to suggest the existence of a regulatory mechanism for the synchronization of follicular maturation and midcycle endometrial development. Further study of the factors involved in this mechanism may result in a better understanding of certain forms of unexplained infertility.

Elisabeth Johannisson

Papers

Endometrial morphology and peripheral hormone levels in women with regular menstrual cycles

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

Pharmacokinetic and Pharmacodynamic Effects of Small Doses of Norethisterone Released from Vaginal Rings Continuously During 90 Days

Endometrial Morphology and Peripheral Hormone Levels in Women with Regular Menstrual Cycles

Cyclic changes in human endometrial surface glycoproteins: a quantitative histochemical study.