Скачать или смотреть When progesterone levels are abundant, it promotes the release of estrogen from the tissues

When progesterone levels are abundant, it promotes the release of estrogen from the tissues. And vice versa. When progesterone is lower, estrogen is retained in the tissue. This is particularly important because tissues can act as reservoirs for estrogen, holding onto it even when circulating levels in the blood are low. The release of estrogen from these reservoirs is a natural response to maintain hormonal equilibrium and ensure that the body has adequate levels of estrogen for its various functions. Breast tissue is particularly sensitive to the estrogen/progesterone ratio. • Premenopausal Women: In premenopausal women, the ratio of estrogen receptors to progesterone receptors in breast tissue is often estimated to be about 3:1 to 4:1, meaning there are typically three to four times more estrogen receptors than progesterone receptors. • Postmenopausal Women: The ratio can change after menopause, as the transition to menopause is marked by a progressively higher density of estrogen receptors (ER) and decreasing progesterone receptors. This sensitivity means that even small changes in estrogen levels can significantly impact breast tissue. Sufficient levels of progesterone stimulate the thyroid gland to produce thyroid peroxidase (TPO), a critical enzyme required for the production of thyroid hormones. Additionally, progesterone helps release thyroxine (T4) from the thyroid gland, allowing it to function on cells throughout the body. If progesterone levels are low and estrogen levels are high, thyroid function may be impaired. Estrogen stimulates the liver to produce thyroid binding globulin (TBG) which binds to both the active T3 and inactive T4 hormones preventing their function on cells.