Androgens

Androgens are a group of steroid hormones that play a key role in the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. They are also present in females, albeit in lower amounts. The primary and most well-known androgen is testosterone, but other androgens include dihydrotestosterone (DHT) and androstenedione.

Function

Androgens are responsible for the development of male secondary sexual characteristics such as increased muscle and bone mass, and the growth of body hair. They also influence the function of many organs, including the reproductive system, musculoskeletal system, and central nervous system.

Biosynthesis

Androgens are synthesized in the adrenal glands, the testes in males, and the ovaries in females. The process of androgen synthesis involves the conversion of cholesterol into pregnenolone, which is then converted into various androgens through a series of enzymatic reactions.

Mechanism of Action

Androgens exert their effects by binding to androgen receptors, which are present in various tissues throughout the body. Upon binding, the androgen-receptor complex translocates to the cell nucleus, where it can influence the expression of specific genes, leading to the physiological effects associated with androgens.

Clinical Significance

Abnormal levels of androgens can lead to various medical conditions. In males, low levels of androgens can result in hypogonadism, characterized by reduced libido, fatigue, and decreased muscle mass. In females, excessive androgen levels can lead to conditions such as polycystic ovary syndrome (PCOS), which is associated with irregular menstrual cycles, hirsutism, and infertility.

Therapeutic Uses

Androgens and their synthetic derivatives, known as anabolic steroids, are used therapeutically in various conditions. They can be prescribed for testosterone replacement therapy in males with hypogonadism, and in certain cases, they are used to treat breast cancer in females. However, the misuse of anabolic steroids for performance enhancement in sports is a significant concern due to potential adverse effects.

See Also

• Testosterone
• Dihydrotestosterone
• Androgen receptor
• Hypogonadism
• Polycystic ovary syndrome
• Anabolic steroids