Hormones: Understanding Their World

Hormones create major physical and mental differences between the sexes.

For men, the major player is testosterone; in women, estrogen is the dominant hormone.

With the reality of an aging population, the doors to questions about the cycles of all hormones in both sexes have been opened. All aging adults experience multiple hormonal adjustments over a life time, that affect mind, body and spirit.

A hormone imbalance is a complex problem to solve because many hormones interact. In women, for example, estrogen enhances the activity of specific genes within a cell. Its partner hormone, progesterone, acts as a counterbalancing agent. At times, the powers of progesterone rule body and mind. Dilemmas regarding estrogen therefore, cannot be solved with out an understanding of its special relationship with progesterone. In turn the highs and lows of estrogen affect many other hormones like insulin, thyroid, or melatonin.

Replacement therapy, a term originally coined as the addition of estrogen after menopause, has expanded into many hormone offerings for both sexes. (In the United States), DHEA and melatonin are sold over the counter. Thyroid hormone is available by prescription. In the future growth hormone may be an option for the elderly individual. Although, it is a natural instinct to ease the ageing process prudence is recommended when considering hormone replacements. .

The Birth of Sex Hormones

Sexual hormones are present long before birth. They set the stage for male and female physical and psychological traits. With 30 to 90 days following birth, then production of these hormones is decreased to small amounts. Their concentration begins to rise gain only when the brain sends a message to the ovaries and testes. The message signals the passage into sexual maturity.

The timing of this event is still a mystery. It is the hypothalamus, in the brain that acts as the biological clock, monitoring the beginning and ending of growth and sexual development.

There are a number of key factors that affect this process, namely heredity, age,

Body fat, and stress. The hypothalamus then initiates the production of chemical messengers, destined to transform the child into the adult and so on.

Estrogen and testosterone are powerful chemicals that always warrant cautious usage. Women, more often than men, may feel victimized by these hormones. Unlike the steady flow of testosterone in men, women experience recurring fluctuations of estrogen and progesterone. Childbearing and lactation place stresses on the woman’s

body composition, energy and emotions. By menopause, a woman could have experienced decades of a love/hate relationship with sexual hormones.

What is a Hormone?

A hormone is like the conductor of an orchestra.

The many hormones that trigger changes during puberty are visual proof of the work credited to estrogen and testosterone. With the help of human growth hormone, estrogen and testosterone coordinate every aspect of female and male maturation. Estrogen and testosterone are really families of hormones.

 Estrogen is the surname for a family of closely related hormones. Each estrogen has a specific role and is distinguished by its power to modify the activity the activity of cells sensitive to each specific hormone. Estradiol, estrone, and estriol and five other estrogens constitute the members of the estrogen family. The variations in structure determine the tasks assigned to each hormone.

Estradiol dominates the circulation from puberty to menopause, and is by far, the most powerful estrogen. When the brain and body agree that the time for reproduction is drawing to a close, the need for estradiol no longer exists and secretion from the ovaries will cease. As the ovaries stop functioning, all cells sensitive to estrogen will experience the shock of estradiol’s inevitable disappearance. Estradiol is chiefly manufactured in the ovaries while a small amount is created in the adrenal glands.

The second most powerful estrogen is estrone which becomes the most powerful after menopause. It is mainly manufactured by the fat cells of the body while a small amount s produced by the liver. Estrone cannot sustain the reproductive functions of the female body nor substitute equally for estradiol’s work in the brain, bones, or heart. It’s continued presence may have a negative effect on breast cells over the decades of a woman’s life.

Estriol, the third estrogen, is dominant during pregnancy, and is manufactured by the placenta, and in minute amounts by the liver. Estriol offers only weak support to aging bones and the heart. It is thought to add little or no risk to the breast for cancer.

Each one of these estrogens can be considered as a possible replacement after menopause.

The Testosterone Family

Testosterone, produced by the testes, is metabolized into many other steroid products.

The most active one is dihydrotestosterone (DHT). Tiny variations in shape are reflected in vastly different stimuli to testosterone-sensitive cells.

Progesterone

There is only one chemical form of progesterone and its structure is similar to testosterone. It is said to have androgen-like qualities. (An androgen is a male hormone)

A hormone’s power is measured by its ability of influence the activity of the various cells in the body. Nature has created a system to regulate cells interaction with hormones. The liver binds a protein around estradiol, estrone, estriol, testosterone, and dihydrotestosterone. As long as the hormone remains surrounded by or bound to TEBG, it is totally inactive. Only a small fraction of hormones circulate in the bloodstream separated from TEBG, free to accomplish their assigned task within specific cells. The protein is called testosterone-estrogen binding globulin or TEBG. As hormone levels diminish over decades of life, less TEBG is produced.

The increase of active hormones in the body does play a role in the creation of some specific types of cancer. The exact risk is difficult to calculate since the number of free hormone molecules is modified by one’s lifestyle and age.

The hormones in the body communicate to other cells in the body based upon their specific shape. Cells in our bodies produce proteins called receptors that recognize a hormone by its shape. As the blood circulates, hormones traveling in the bloodstream can enter any cell. When a cell is designed to interact with a particular hormone, receptors for that specific hormone will be present. A receptor in each cell is chemically designed to fit perfectly with just one specific hormone. As the blood transports individual hormones past a cell surface, (the cell membrane), the receptor and hormone are chemically attracted to each other like magnets of opposite charge. The chemical attraction of the receptor and the hormone together is called affinity or binding power.

The binding of a hormone to a receptor will determine the amount of work that will be accomplished by that specific hormone. When the affinity is weak, the hormone is more likely to escape the grasp of the receptor and be ineffective. Each hormone has its own receptors.

The affinity of progesterone to its receptor equals the binding of the estradiol-receptor complex. Thus progesterone has the power to alter the actions of estradiol.

The level of testosterone remains relatively unchanged in men through early adult year. In contract, for women the various estrogen molecules fluctuate throughout the years between the first and the last menses. Most women are aware of the brain and body changes a progesterone takes control just before menses. For some women, the quality of life can be seriously affected by premenstrual hormone imbalances. Monthly fluctuations of estrogen to progesterone do affect mind and body.

Changes in the effective concentration of estrogen can produce an array of unacceptable feeling. Symptoms, such as anxiety, bloating, sleeplessness, breast sensitivity or moodiness are common problems that reflect the controlling activities of progesterone.

The gradual depletion of sexual hormones, will inevitably lead to noticeable aging changes in most individuals regardless of sex.