Estrogens gestagens, their homologues and antagonists

Natural follicular hormones are ovarian-derived estradiol, estrone and estriol. These hormones are called estrogens due to the fact that they cause estrus in castrated female animals (estrus).
Together with the corpus luteum hormone, follicular hormones are involved in the regulation of the menstrual cycle and the function of childbirth. During pregnancy, the production of follicular hormones increases significantly and large amounts of them are excreted in the urine.
According to modern data, there are specialized receptors for estrogens in the corresponding organs (target organs), through interaction with which their effects are realized.
When introduced into the body, estrogenic drugs (of natural and synthetic origin) cause a specific estrogenic effect: endometrial proliferation, stimulate the formation of the uterus and secondary female sexual characteristics, especially with their underdevelopment, soften and eliminate general disorders (osteoporosis, atherosclerosis, atrophy of the skin and mucous membranes of the genitourinary system ), arising in the body of women on the basis of insufficiency of the gonads in the climacteric period or after gynecological operations (oophorectomy). Estrogens are involved in the formation and maintenance of bone strength, reduce its resorption, normalize the balance between osteoblasts and osteoclasts (both cells contain estrogen receptors). Therefore, a violation of the production of estrogens in the body (in menopause, during ovariectomy, etc.) is accompanied by an increase in bone resorption, the development of osteoporosis and an increase in bone fragility.