Description
Testosterone, a C19-Steroid, is the most effective natural hormone in the family of androgens.
In males, it is mainly produced in the Leydig cells of the testes, only a small amount is produced in the adrenal cortex. On the whole, adult males have 10 to 20 fold higher testosterone plasma concentrations than females. In the circulation, the main part of testosterone is bound to plasma proteins like sex hormone binding globuline (SHBG) and albumine. Only 1 – 2 % of the testosterone is unbound and therefore biologically active. The free testosterone is released via the salivary glands. In their cells a great part of the hormone is transformed to 5-Dihydrotestosterone. Nevertheless, the concentration of testosterone in saliva reflects the level of free testosterone in plasma. Testosterone levels in females should be measured in patients having clinical symptoms of virilism caused by the adrenogenital syndrome, the polycystic ovary syndrome or neoplasms of the adrenal cortex or the ovaries. Due to the fluctuations, repeated measurements are recommended. In men with signs of primary or secondary hypogonadism, confirmatory testosterone levels can be determined. Testosterone together with cortisol levels represents a useful parameter in stress research and sports medicine. Measurement of testosterone is often used by healthcare providers, in the aid of diagnosis and treatment of disorders involving the male sex hormones (androgens), including primary and secondary hypogonadism, impotence in males and in females hirsutism (excessive hair) and virilization (masculinization) due to tumors, polycystic ovaries and adrenogenital syndromes.
