Hormones, part 2
Female sex hormones
Atlas company blog, Geektimes
We have discussed male sex hormones, and now it is logical to talk about female ones. Estrogen and progesterone not only guide puberty and reproductive functions, they are associated with the work of the brain and are involved in the regulation of the immune and cardiovascular systems.
Estrogens
Female sex hormones, like men's, belong to steroids – substances that dissolve not in water, but in fat. In the female body, they are synthesized by ovarian follicles, and in the male body, by testicles (in much lower concentrations). In both sexes, estrogens are produced in the adrenal cortex and, according to research, directly in the brain. Estrogens are synthesized both from androgens (testosterone and androstenedione) and directly from cholesterol.
In women, estrogens begin to be produced even in the prenatal period, when the ovaries form in the embryo at about 10 weeks of pregnancy. With the onset of menstruation, the level of estrogen changes during the cycle – it begins to rise from the first day, reaches a peak before ovulation, then decreases, and drops sharply 1-2 days before the start of menstruation. After menopause, a woman's estrogen level decreases and continues to remain stably low.
Estrogens are responsible for the feminization of the body, participate in puberty, support the menstrual cycle and prepare the body for pregnancy. Estrogens suppress lactation (and lactation, in turn, suppresses the activity of estrogens). In addition, estrogens are involved in the fermentation of fats, increase the level of "good cholesterol" (HDL) and reduce the level of "bad" (LDL), protect blood vessels from the formation of cholesterol plaques.
Estrogens have a double effect – "fast" and "slow". "Slow" reactions are associated with the effect on gene activity. Like other steroids, estrogens can enter the cell, bind to intracellular receptors and activate or suppress the expression of certain genes. It takes a lot of time – the body's reaction to changes in estrogen levels can occur only after an hour. The "rapid" response to the actions of estrogens occurs due to their interference in other cascade reactions and the work of brain neurons. It takes several minutes to form a response. To carry out such reactions, estrogens are synthesized directly in the central nervous system: the aromatase enzyme processes them from testosterone.
In the brain, estrogens behave almost like neurotransmitters. They have an effect on the receptors of acetylcholine, glutamate and serotonin. Therefore, estrogens are involved in the processes of learning and memorization, regulates mood, appetite and sleep. They interact with opioid receptors – and thus affect sensitivity to pain. Estrogens support the transmission of signals to the central nervous system and help form new neural connections, which improves the plasticity and regeneration of nervous tissue. All these processes occur in both women and men.
Estrogens include three substances – estradiol, estriol and estrol. Of these, estradiol has the strongest effect (it is formed from testosterone). The concentration of estriol begins to prevail over estradiol after menopause and during pregnancy.
A decrease in estrogen levels – for example, before the onset of menstruation or after menopause – can cause mood changes, memory impairment, insomnia and migraines.
Progesterone
Estrogens play an active role in a woman's life before pregnancy, and then pass the baton to progestins (progestogens). This is the second group of steroid female hormones that are synthesized in the corpus luteum, placenta and in the adrenal cortex. The yellow body is a gland that is formed under the action of luteinizing hormone (LH) in the second phase of the cycle. It is formed after ovulation and is responsible for preparing the body for pregnancy. If pregnancy does not occur, the yellow body curtails its activity, after which the level of progesterone production decreases – and after a while menstruation comes.
Chorionic gonadotropin can extend the "service life" of the corpus luteum. This hormone begins to be produced in the female body from the first days of pregnancy (it is used for home pregnancy tests). By the way, if you have heard that hCG is normally present in men, and that their pregnancy tests will always be positive – do not believe it: hCG is absent in non-pregnant people, and if the analysis has determined it, then this may signal the development of oncological diseases.
Due to the activity of hCG, the yellow body persists for another 10-11 weeks – until the placenta begins to independently produce progesterone and estrogens. Progesterone levels will rise throughout the pregnancy and plummet a few days before delivery. A high level of progesterone together with prolactin suppresses the activity of follicle-stimulating hormone (FSH), without which follicles do not form and ovulation does not occur.
Progesterone reduces contractions of the uterus and fallopian tubes (pregnant women do not need such activity) and helps the body prepare for lactation. It stimulates the renewal of breast cells, so too high a level of this hormone increases the risk of breast cancer after menopause.
In the central nervous system, progesterone reduces sensitivity to serotonin and histamine, a neurotransmitter of inflammation. Progesterone has an effect on appetite and can lead to weight gain – in both men and women. In the male body, progesterone is involved in sperm formation.
Relaxin
It is a nonsteroidal hormone associated with pregnancy in women. In its structure, relaxin is similar to insulin. In the female body, it accompanies progesterones – it is secreted by the yellow body after ovulation; at the onset of pregnancy, relaxin begins to be produced by the placenta. The peak level of relaxin occurs at 14 weeks and then at the time of delivery. In men, relaxin affects sperm motility.
Oral contraception
The interaction of estrogen and progesterone can be used to prevent pregnancy. According to this principle, female hormonal contraception is built, which suppresses ovulation. These can be both combined oral contraceptives (COCs), which include estrogens and progestogens, and single–component ones (the only component is progesterone). All of them suppress ovulation and increase mucus secretion in the cervix, so that spermatozoa cannot overcome this barrier.
Each drug has its own characteristics and side effects. A synthetic molecule of estradiol – ethinyl-estradiol – was developed in the 1940s; it is its features that cause the main side effects of hormone therapy. If the patient has a predisposition, then ethinyl-estradiol increases the risk of thrombosis and cardiovascular diseases. Bioequivalent drugs are gaining popularity now, the effect of which is as close as possible to the "native", endogenous estradiol and does not cause side effects.
Postmenopause
If andropause occurs unnoticeably in men, then this process is more obvious in women. Gradually, at the age of 45-55, the frequency and duration of menstruation decreases in a woman, and over time they completely pass. The level of estrogens during menopause decreases significantly, not estradiol comes to the fore, but estriol – the lightest hormone of estrogens.
The transition period can be accompanied by increased sweating, sleep disorders, headaches, decreased attention and even depression – bad mood and loss of interest in life. During postmenopause, the risk of breast cancer increases, and in older age – dementia.
To relieve menopausal symptoms, a woman can use hormone replacement therapy. If you start treatment immediately during menopause (up to 59 years), it will help to maintain healthy blood vessels and good memory for longer and reduce the risk of cardiovascular diseases.
Side effects depend on the patient's state of health, medical history, genetic background and the chosen medication. Combined drugs, which include estrogen and progesterone, increase the risk of breast cancer. At the same time, hormonal agents consisting only of estrogens and bioequivalent agents do not affect the risk of cancer in people who are not predisposed to them.
Hormone therapy, whether it is contraception or postmenopausal support, offers many options: it can be different combinations and dosages of drugs, bioidentical formulas of molecules, alternative methods of administration (patches and gels). To choose a safe drug, it is necessary to consult with an obstetrician–gynecologist and discuss personal risks of cardiovascular and oncological diseases, medical history, genetic factors. Readers of "Giktimes" and their relatives get a 15% discount on the initial appointment of a gynecologist at the Atlas clinic.
Portal "Eternal youth" http://vechnayamolodost.ru
25.10.2016