What are hormones and what is it they do?
Hormones are chemical messengers that travel via the blood, enter tissues and regulate cell function by direct effects on Specific receptors. Hormones act on receptors the way a key fits into a lock. If the hormone is slightly different, it may fit into the lock but not open the same doors as the proper key.
Where are hormones made?
The hormones we are discussing today are estrogens, androgens; progesterone and cortisol are known as steroid hormones. Steroid hormones are manufactured in the body from cholesterol. Women and men share the same hormones. The relative amounts differ.
There are four general categories of steroid hormones: Estrogens, androgens, progesterone and glucocorticoids. Estrogens are called female hormones but are essential for men. Androgens are called male hormones but are also essential for women. Progesterone is the only hormone in its class but it can be changed into cortisol. Cortisol, the stress response hormone, is a glucocorticoid. In women, sex steroid hormones are produced primarily by the ovaries and adrenal glands.
In men, sex steroids are produced primarily by the testies and adrenal glands. The conversion of each hormone to another in the pathway requires specific enzymes, which in turn require specific vitamins and minerals. Once menopause or andropause has been reached the adrenal glands become the primary source for estrogens and testosterone.
Estrogens
Estrogen receptors are found in cells throughout the body including bone, brain, blood vessels, bladder, breast, thyroid gland, and the reproductive organs. Estrogens are responsible for the development of the female secondary sex characteristics such as breast development and play a critical role in the menstrual cycle.
In men estrogens are related to libido, adiposity, skin tissues and prostate. All estrogens interact with estrogen receptors but not to the same degree. Each estrogen has a different affinity for the estrogen receptor. The stronger the affinity for the receptor the greater estrogenic effect it will have. There are many naturally occurring human estrogens. The most widely used are estradiol, estrone and estriol.
Estradiol
Estradiol is the strongest of the three major estrogens and is the main estrogen released by the ovaries. It is also produced by the adrenal glands. Estradiol is the primary estrogen of the menstrual cycle and is responsible for maintaining the endometrium (the lining of the uterus).
Estrone
Estrone is next in strength after estradiol. It is produced from androstenedione released by the adrenal glands. Estrone is the main post-menopausal estrogen, and can be converted to either estriol or estradiol as needed.
Estriol
Estriol is the weakest of the three common natural estrogens but is strong enough to produce estrogenic effects. Estriol levels are very high during pregnancy.
Progesterone
Progesterone promotes gestation and is essential for the maintenance of pregnancy and the principal hormone of the second half of the menstrual cycle, the luteal phase. Progesterone receptors are found throughout the body just like estrogens receptors. The body's tissues need all hormones for a true balance. Progesterone is produced in the ovaries and the adrenal glands but most of the adrenal p4 goes to cortisol
Synthetic progestins, much like synthetic estrogen, do not fit into the same receptor "locks" and the natural hormones (or bio-identical).
Androgens and Androgen Precursors
Testosterone
In women provides a sense of well-being, improves libido (sex drive), helps maintain the vaginal mucosa and bone tissue. It is also needed for heart health, skin elasticity and muscle mass. Women have 1/5 to 1/10 the amount of testosterone as men. Testosterone can be converted to estraiol via the enzyme aromatase that are found in fat cells. The more fat cells the more estrogen, which is true for women as well as men.
Dehydroepiandrosterone
Dhea is the most abundant steroid hormone in the body and is the principle androgen precursor. Dhea is produced by the adrenal glands and can be used to make estradiol, estrone, estriol, and testosterone.
Androstenedione
Androstenedione is made from Dhea in the adrenal glands. It is the building block for estrogens and testosterone and is critical for the production of steroid hormones after menopause.
Glucocorticoids
Cortisol is released by the adrenal glands in response to physical and emotional stresses. It is essential in mobilizing the body's defenses against infection and inflammation.
Levels are highest in the am to combat the stress of overnight fasting and to start the breakdown of proteins into simple sugars to provide glucose to the brain.
Hormone Interactions
The interactions between various hormone groups are as important as the actions of the hormones themselves.
Estrogen and Cortisol
Estrogens are made from androstenedione and testosterone via the action of the enzyme aromatase. Cortisol stimulates aromatase activity, which in turns promotes estrogen formation. Cortisol also promotes deposition of fat around the waist, which is where the aromatase. Therefore excess cortisol translates into excess estrogen in both men and women.
Progesterone and Cortisol
P4 interacts directly with cortisol at the receptor level. These two complete for the same receptor and therefore if there is a lot of stress and a lot cortisol the cortisol may block the actions of p4.
Dhea and Cortisol
Dhea and cortisol have opposite effects on immune function and regulation of blood sugar. Dhea can improve sensitivity to insulin, which helps lower blood glucose levels. Cortisol increases blood glucose levels. When cortisol levels are high, more Dhea must be released to balance the effects of cortisol.
Androgens and Cortisol
The ration between cortisol and androgenic hormones is essential for maintaining muscle mass. Androgens build muscle, cortisol breaks it down. As we age, or when stressed, we tend to have more cortisol relative to androgens which results in a net loss of muscle mass and bone. Cortisol and androgens can act on the same gene in opposite ways, so cortisol can directly oppose the message that the androgen is trying to deliver.
Thyroid and Cortisol
They have a mutually dependent relationship. A certain amount of thyroid is needed for cortisol to work properly, and a certain amount of cortisol is necessary for thyroid hormones to work properly. This means that the signs and symptoms of a deficiency in one hormone family can actually be due to a deficiency in the other hormone family. An excess of cortisol can impair the activity of thyroid.
Hormone Balance
Progesterone and Estrogens
Estrogen and progesterone receptors are found in the same tissue and need to be in balance for optimum action. Too much of one produces symptoms of a deficiency of the other. Hormone replacement is the attempt to restore the balance needed to be symptom free.
Estrogens and Thyroid Hormones
Excess estrogens suppress the action of thyroid hormones in men and women. Remember the aromatase action producing estrogen from testosterone. Progesterone can assist the action of thyroid.
Functional Deficiency
Menopause and andropause symptoms are essentially the results of hormone imbalances. These imbalances and therefore symptoms can occur at any time due to any number of reasons.
No comments:
Post a Comment