The androgen testosterone (17β‑hydroxyandrostenone) has a molecular weight of 288 daltons. In men, testosterone is synthesized almost exclusively by the Leydig cells of the testes. The secretion of testosterone is regulated by luteinizing hormone (LH), and is subject to negative feedback via the pituitary and hypothalamus.
Testosterone promotes the development of the secondary sex characteristics in men and serves to maintain the function of the prostate and seminal vesicles. Most of the circulating testosterone is bound to carrier proteins (SHBG = sex hormone‑binding globulin). In women, small quantities of testosterone are formed in the ovaries. In physiological concentrations, androgens have no specific effects in women. Increased production of testosterone in women can cause virilization (depending on the increase).
Method: The electrochemiluminescence immunoassay “ECLIA”
| Test subjects | ng/ml | ng/dL | nmol/L |
| Males 20-49 years | 2.49-8.36 | 249-836 | 8.64-29.0 |
| Males ≥ 50 years | 1.93-7.40 | 193-740 | 6.68-25.7 |
| Females 20-49 years | 0.084-0.481 | 8.40-48.1 | 0.290-1.67 |
| Females ≥ 50 years | 0.029-0.408 | 2.90-40.8 | 0.101-1.42 |