testosteronu

Testosterone, also referred to in some languages as testosteron (with testosteronu as its genitive form in languages such as Czech or Polish), is the primary male sex hormone and a potent androgen. It is produced mainly in the Leydig cells of the testes, with smaller contributions from the adrenal glands; in women, the ovaries and adrenal glands produce lower amounts. Its synthesis is regulated by the hypothalamic-pituitary-gonadal axis, where GnRH stimulates LH and FSH from the pituitary, and LH triggers testosterone production. Testosterone levels are maintained within a physiological range by negative feedback to the hypothalamus and pituitary.

Testosterone supports the development and maintenance of male reproductive tissues, such as the testes and prostate, and drives secondary sexual characteristics including facial and body hair, a deeper voice, and increased muscle mass. It also promotes erythropoiesis, bone density, and plays a role in libido and mood. During puberty, rising levels stimulate growth spurts, spermatogenesis, and bone maturation.

Metabolism of testosterone involves its conversion to dihydrotestosterone (DHT) by 5-alpha-reductase and to estradiol by aromatase. DHT mediates several androgenic effects, while estradiol contributes to bone health and other tissues in both sexes.

Clinically, testosterone is used to treat male hypogonadism and in certain transgender hormone therapies. Administration methods include injections, topical gels or patches, and implants. Monitoring typically includes serum testosterone levels, hematocrit, and prostate-specific antigen. Potential risks include polycythemia, cardiovascular events, and prostate-related issues; use is contraindicated in certain cancers and during pregnancy.