Androgens are steroid hormones that are responsible for the male principle: the development and functioning of the male reproductive system, the maintenance of normal sperm levels and unobtrusive male appearance.
Where is testosterone produced?
Testicles are the main source of testosterone in the body. Testosterone (5-12 mg / day) and small amounts of dehydroepiandrosterone (DHA), androstenedione and estrogens are produced in this organ.
Although all testicular tissues are capable of producing testosterone, Leydig cells are the main producers. Tubular epithelium of the testicles and adrenal glands are also capable of producing this hormone. They produce DHA, which is converted to testosterone through a chain of reactions. But this fraction contributes a lot to the main group of androgens (see below). More details “the role of adrenal androgens in the male body”).
Any hormone, any enzyme and secret is synthesized from a certain substance that enters our body with food. Testosterone is based on cholesterol. Leydig cells receive cholesterol from the blood as acetic or low-density lipoproteins. A certain sequence of reactions occurs with the transformation of substances: cholesterol → pregnenolone → 17-hydroxypregnenolone → androstenediol. After chemical reactions, 2 androstenediol molecules are combined with each other and the final product → testosterone comes out.
Effects of testosterone
No wonder testosterone is called”the hormone of Kings – The King of hormones.” After all, it controls almost all functions in the male body. A hormone can do this directly – penetrating directly into the nucleus of cells or indirectly-controlling the work of other hormones.
Testosterone in the male body performs the main classical functions:
- Androgenic function-testosterone provides the manifestation of secondary sexual characteristics in men. Due to the high content of testosterone, which predominates over estrogens, hair growth occurs in men (hair growth on the face, chest, buttocks and genitals), the growth and development of male genital gonads and external genitalia, male body type (distribution of adipose tissue) is provided. Hair loss and baldness also control testosterone. Interestingly, body fat is also controlled by testosterone. If women have superficial obesity, due to subcutaneous adipose tissue, then in men, fat is deposited in the parenchymal organs and in the greater aroma.
- Anabolic function-a sex steroid ensures the growth of muscle fibers, the required bone density, participates in the production of the necessary organ-specific proteins in the kidneys, liver, sweat and sebaceous glands.
- Antigonadotropic function-the high content of testosterone inhibits gonadotropins. The general principles of silent feedback between the gonads and the hypothalamic-pituitary system are met.
- Reproductive function-without the required amount of testosterone, the formation of sperm is impossible. The hormone is the” driver ” of spermatogenesis. It also provides erectile function and libido.
- Psychophysiological function-thanks to the male sex steroid, stereotypes of behavior and certain character traits are formed. It is testosterone that provides the desired libido, increased aggression in behavior, the desire to fight and the quenching of fear. The hormone has a psychostimulating effect.
- Hematopoietic function-indirectly affects hematopoiesis. Testosterone can act on erythropoiesis in the red bone marrow, increasing it. It also has an effect on the production of erythropoietin in the kidneys. The ratio of erythropoietin to testosterone works on the principle of a direct positive relationship – the more testosterone, the more erythropoietin is produced.