Alarelin

Alarelin has a high affinity for the gonadotropin - releasing hormone (GnRH) receptors on the surface of pituitary gonadotroph cells and can compete with endogenous GnRH for these receptors. Continuous use of alarelin can desensitize the GnRH receptors of pituitary cells, thereby inhibiting the pituitary gland from secreting gonadotropins (follicle - stimulating hormone FSH and luteinizing hormone LH). Ultimately, this reduces the secretion of sex hormones in the ovaries and testes, resulting in a hypoestrogenic or hypoandrogenic state in the body. Some studies have also found that alarelin may have a direct inhibitory effect on certain tumor cells. It can induce apoptosis of tumor cells and inhibit their growth and spread by affecting the signal pathways related to tumor cell proliferation and apoptosis. In addition, it may also be involved in regulating the body's immune function, etc., but the specific mechanisms still need further in - depth research. Alarelin is one of the commonly used drugs for the treatment of endometriosis. By suppressing ovarian function and reducing the level of estrogen in the body, it causes the ectopic endometrial tissue to atrophy, thus alleviating symptoms such as dysmenorrhea and dyspareunia, reducing the size of pelvic masses, and decreasing the recurrence rate of endometriosis. It can also be used to treat uterine fibroids, reducing the size of the fibroids and relieving symptoms such as menorrhagia, anemia, frequent urination, and abdominal pain caused by fibroids. It is especially suitable for reducing the size of fibroids before surgery to facilitate surgical operation and reduce intraoperative bleeding. It can also be used for patients approaching menopause to induce amenorrhea in advance and cause the fibroids to atrophy naturally. In assisted reproductive technologies such as in - vitro fertilization - embryo transfer (IVF - ET), alarelin is often used for pituitary down - regulation in long - term or ultra - short - term protocols. By inhibiting the occurrence of the endogenous LH surge, it enables multiple follicles to develop synchronously, increases the number of retrieved eggs and high - quality embryos, and thus improves the success rate of IVF - ET. For children with central precocious puberty, alarelin can inhibit the function of the hypothalamic - pituitary - gonadal axis, delay the development of secondary sexual characteristics, and inhibit premature skeletal maturation, thereby improving the adult height of the affected children.