Estrogens from Reproductive Life to Menopause From puberty to menopause the ovaries produce estrogen (estradiol) and, when ovulation occurs, progesterone . The ovaries also produce the male hormones testosterone and androstenedione. Estrogen and progesterone act on their target organs, so called because they contain specific receptors or receiving areas where these hormones can enter the cell and produce the required effect. Such target organs for estrogen and progesterone are the breasts, vulva, vagina, uterus , urethra, bladder, skin and parts of the brain that control mood, sleep (insomnia) and temperature (hot flashes).
After menopause, the ovaries secrete very little estradiol, and so the total amount of estrogen in the body drops to only a fraction of that produced during reproductive life. As a result, an alternative though small source of estrogen becomes significant. Male hormones continue to be produced by the adrenal gland and are carried to the skin, liver, body fat and brain, where they are converted to a weak but effective estrogen, estrone. Body fat is a particularly important site of estrone production; it has long been recognized that fatter women have higher circulating estrone levels.
Why Is Estrogen Important? The degree to which estrogen affects the tissues becomes evident after menopause, when levels of estrogen drop. Postmenopausal estrogen deficiency causes obvious symptoms such as hot flashes, insomnia, vaginal dryness, increased urinary frequency, increased incidence of bladder and vaginal infections and the long-term estrogen-deficiency diseases such as osteoporosis and a predisposition to arteriosclerosis. Often the problems of heart disease and osteoporosis remain unrecognized until many years
