Implantation Window and Angiogenesis.

In recent decades, infertility is one of the health problems worldwide. One of the most crucial events in reproductive period is implantation window (IW). In the time after IW period, the embryo cannot connect to the endometrium; therefore the most critical issue for successful implantation is timely entrance of embryo to the uterine cavity during the IW. Implantation failure is responsible for many cases of infertility and is the most important limiting factor for achieving a successful outcome using the assisted reproductive techniques (ART). The aim of this study was to investigate the receptivity of the endometrium and factors affecting it with emphasizing on the role of angiogenesis. Interaction between the embryo and the endometrium is affected by molecular interactions among cytokines, growth factors, hormones, and cell adhesion molecules, causing endometrial receptivity. Also, angiogenesis is a process that has an important role in human implantation. Estrogen and progesterone hormones are two important regulation keys in angiogenesis and implantation process. It is expected that effective and stimulating drugs of angiogenesis can improve the characteristics of endometrial receptivity and prevent implantation failure in ART. It is hoped that with recent advances in the field of molecular medicine, improvement of angiogenesis in human endometrium and prevention of the implantation failure be achieved. Here, we summarized various factors could affect on endometrial receptivity and the role of them on angiogenesis. J. Cell. Biochem. 118: 4141-4151, 2017. © 2017 Wiley Periodicals, Inc.

Evaluation of Progesterone and Ovulation-stimulating Drugs on the Glandular Epithelium and Angiogenesis in Mice.

BACKGROUND: Human endometrium is a dynamic tissue during the menstrual cycle can be influenced by ovarian hormones. The purpose of this study was to evaluate the endometrium angiogenesis under the influence of human menopausal gonadotropin and human chorionic gonadotropin (HMG and HCG) that stimulate ovulation and progesterone. MATERIALS AND METHODS: In this study, thirty adult female mice were randomly divided into three groups as: control, gonadotropin and gonadotropin + progesterone. The mice in the other two groups except the control group received 7.5 IU HMG and later HCG. Subsequently, the mice were placed in a cage for mating. Gonadotropin + progesterone group was administered, 1 mg/mouse progesterone in 24, 48, and 72 h interval, after HMG injection. Ninety-six hours after HMG injection, animals were sacrificed, and their uterine specimens were prepared by immunohistochemistry technique for light microscopic studies, and statistical analysis was carried out. RESULTS: Endometrium angiogenesis in control group showed that mean ± standard deviation was 24.15 ± 11.15, gonadotropin group was 62.50 ± 24.16, and gonadotropin + progesterone group was 41.85 ± 19.54. Significant difference between the control group and gonadotropin group and between the control group and gonadotropin + progesterone was observed. Statistically significant differences were observed in all groups in the endometrial angiogenesis (P < 0.05). CONCLUSION: Ovarian induction with gonadotropins and gonadotropins + progesterone could not change the morphometrically index of endometrial glandular epithelium in mice. Ovarian stimulation followed by progesterone injection could modify the angiogenesis of mice endometrium.