Testosterone: The Male Sex Hormone

The document provides a comprehensive overview of testosterone, a male sex hormone. It is primarily produced by the testes and is responsible for the development of male genitalia, reproductive glands, and ducts. Testosterone is synthesized from cholesterol by Leydig cells in the testes, with over 95% of testosterone in male blood being synthesized by testicular secretion. The hormone mediates basic sexual processes and controls secondary male characteristics. High testosterone levels have been linked to longer, healthier lives and preserved sexual potency, while low levels have been associated with dementia and coronary artery disease. Testosterone is used in treating male hypogonadism and breast cancer. Disorders such as polycystic ovarian syndrome (PCOS), adrenal virilization/adrenal tumors, and others can cause an overproduction of androgens. Reduced testosterone production can be caused by factors like age, certain drugs, chemotherapy, and genetic disorders like Klinefelter and Kallmann syndrome. The document concludes by stating that more research is needed to understand how aromatization contributes to the maintenance of androgen activity in mature male animals.