Androgens – the general collective name for a group of steroid male sex hormones produced by the sex glands (testes in men and ovaries in women) and the adrenal cortex and possessing the property in certain concentrations to cause androgenesis, virilization of the body – the development of male secondary sexual characteristics – in both sexes.
Androgens have strong anabolic and anti-catabolic effects, increase protein synthesis and inhibit protein breakdown.
Increase the utilization of glucose by cells by increasing the activity of hexokinase and other glycolytic enzymes.
Lower blood glucose levels.
Increase muscle mass and strength.
Contributes to a decrease in total body fat and a decrease in fat mass in relation to muscle mass, but can increase the deposition of male-type fat (on the abdomen) while reducing fat deposits in typically female areas (buttocks and thighs, breasts).
They lower the level of cholesterol and lipids in the blood, inhibit the development of atherosclerosis and cardiovascular diseases, but to a lesser extent than estrogens (this is partly why men have a shorter life expectancy and cardiovascular diseases are more frequent and develop at a younger age than women).
Androgens increase the excitability of the psychosexual centers of the central nervous system, libido (sexual desire) in both sexes, the frequency and strength of penile erections in men, the strength of the erection of the clitoris in women.
In women, androgens reduce the secretion of vaginal lubricant, which can make vaginal intercourse painful when androgen levels are high in women.
Androgens cause the appearance or development of male secondary sex characteristics:
- lowering and coarsening of the voice,
- male pattern hair growth on the face and body,
- transformation of vellus hair on the face and body into terminal,
- increased sweat secretion and change in its smell,
- in men – an increase in the size of the penis and testicles to a genetically specified maximum, pigmentation of the scrotum and the development of folding of the skin of the scrotum, pigmentation of the nipples,
- the formation of a male type of face and skeleton,
- an increase in the size of the prostate and the amount of secretion in it.
With a certain genetic predisposition (the presence of the enzyme 5-alpha-reductase in the scalp) androgens can cause male-pattern baldness.
In women, androgens at concentrations characteristic of men cause:
In a pregnant woman in the early stages, high concentrations of androgens cause a miscarriage due to the cessation of the growth of the size of the uterus and the “cramped” in the uterus for the fetus, despite the fact that androgens themselves cause relaxation of the muscles of the uterus, like progesterone.
The increased content of sex hormones leads to a decrease in the life expectancy of the body, increasing its wear and tear.
The main hormone of the male sex glands – androgen – is testosterone. According to modern data, testosterone circulating in the blood in target cells is reduced by 5-alpha-reductase to 5-alpha-dihydrosterone, which binds to androgen receptors and penetrates into the cell nucleus; in some tissues, testosterone itself can bind to receptors.
For use in medical practice, testosterone in the form of propionate is obtained synthetically. Testosterone propionate has the biological and medicinal properties of a natural hormone, but it is absorbed more slowly and is more stable in the body.
In addition to the specific androgenic action, drugs of this group have other properties, in particular, they affect nitrogen and phosphorus metabolism. They have anabolic activity, but their androgenic effects hinder the widespread use of these drugs as anabolic agents.
Androgens are prescribed to men, mainly with sexual underdevelopment, functional disorders in the reproductive system, climacteric syndrome, acromegaly. The introduction of androgens to women causes inhibition of the gonadotropic function of the pituitary gland, inhibition of the function of the follicular apparatus and ovaries, endometrial atrophy, and suppression of lactation. Sometimes androgens are prescribed to women for climacteric vascular and nervous disorders in cases where estrogen drugs are contraindicated, for dysfunctional uterine bleeding, as well as for tumors of the genital organs and mammary glands.
Antiandrogens (bicalutamide, flutamide, etc.) are used mainly in oncological practice.
Below is a list of androgens and antiandrogens: