Effect of clomiphene citrate on the synthesis and release of the human beta-lactoglobulin homologue, pregnancy associated endometrial alpha 2-globulin, by the uterine endometrium

Endometrial protein PP14: a new test of endometrial function?

The human endometrium produces a number of proteins which are at least partly specific to that tissue. Two of these proteins have been the subject of much recent work. They were originally called ‘placental protein 12’ and ‘placental protein 14’ (PP12 and PP14) because they were isolated by Hans Bohn from extracts of whole placentae. However, it is now clear that they arise from the maternal endometrium (decidua) rather than the fetal trophoblast. Placental protein 12 has been shown to be identical to the insulin-like growth factor binding protein-1 (IGFBP-1). It is produced in many normal tissues and its measurement probably does not provide a specific index of endometrial function. By contrast, PP14 is detectable only in ‘reproductive’ tissues and, in theory, might be an excellent clinical test of endometrial function.

Glycodelin: a major lipocalin protein of the reproductive axis with diverse actions in cell recognition and differentiation

Glycodelin is a glycoprotein that belongs to the lipocalin superfamily. Depending on glycosylation, glycodelin appears in various isoforms. In the uterus, glycodelin-A is the major progesterone-regulated glycoprotein secreted into uterine luminal cavity by secretory/decidualized endometrial glands. The other tissues expressing glycodelin include fallopian tubes, ovary, breast, seminal vesicle, bone marrow, and eccrine glands. Glycodelin-A potently and dose-dependently inhibits human sperm-egg binding, whereas differently glycosylated glycodelin-S from seminal plasma has no such effect. Absence of contraceptive glycodelin-A in the uterus during periovulatory midcycle is consistent with an open "fertile window." Glycodelin induced by local or systemic administration of progestogens may potentially reduce the fertilizing capacity of sperm in any phase of the menstrual cycle. Glycodelin also has immunosuppressive activity. Its high concentration at the fetomaternal interface may contribute to protection of the embryonic semiallograft. Besides being an epithelial differentiation marker, glycodelin appears to play a role in glandular morphogenesis, as transfection of glycodelin cDNA into a glycodelin-negative breast cancer cells resulted in formation of gland-like structures, restricted proliferation, and induction of other epithelial markers. These various properties, as well as the chemistry, biology, and clinical aspects of glycodelin, continue to be areas of active investigation reviewed in this communication.

Morphometric characteristics of endometrial biopsies after different types of ovarian stimulation for infertility treatment

OBJECTIVE

To investigate whether various types of ovarian stimulation induce differences in endometrial development at the midluteal phase in infertile women.

DESIGN

Assessment of stromal and glandular compartments in endometrial biopsies using morphometric criteria.

SETTING

Institute for Hormone and Fertility Research, Hamburg, Germany.

PATIENTS

The study included 18 women after treatment with human menopausal gonadotropin (hMG)/human chorionic gonadotropin (hCG) (group I), 23 women after clomiphene citrate (CC)/hMG/hCG treatment (group II), and 12 women after CC stimulation (group III).

INTERVENTIONS

Endometrial biopsies and blood samples were taken simultaneously in the early to midluteal phase. To assess the time of ovulation, hormone analysis and regular checks by ultrasonography were performed.

MAIN OUTCOME MEASURES

Morphometric evaluation of glandular and stromal structures revealed an impaired endometrial development after various treatment protocols.

CONCLUSION

Ovarian stimulation in infertile women results in most cases in an elevation of steroid levels; however, the occurrence of an inadequate endometrial development might have an unfavorable influence on the outcome of implantation. Therefore, these findings may be of importance to the choice of treatment for infertility.