The prostate is an organ in males that helps to make semen. At puberty, it becomes functional under the influence of the male hormone testosterone. An enlarged prostate is more common in the elderly and can be from a number of different conditions, most commonly benign prostatic hypertrophy. It is important to consult with a physician for the diagnosis and treatment of prostate conditions and other medical issues.
Physiology and Testosterone
The prostate secretes a milky white to clear fluid that helps sperm survive. In order to function, the prostate needs the male sex hormone testosterone. Testosterone is a steroid hormone produced mainly by the testicles and secondarily by the adrenal glands. Testosterone as an end product is not sufficient to support the prostate, however. Once testosterone enters the prostate cells through the bloodstream, it is converted to dihydrotestosterone, or DHT, by the enzyme 5-alpha-reductase.
Benign Prostatic Hyperplasia
Over time, the effects of dihydrotestosterone are factors that promote the prostate to become nodular and grow too large, particularly around the urethra. The incidence increases with age. Symptoms include a frequent need to void, and difficulty urinating. It also carries an increased risk of infection. It can be diagnosed with a rectal exam, and sometimes ultrasound or biopsy. There are several treatment options, including some that interfere with dihydrotestosterone.
Benign tumors and cancerous tumors have a number of risk factors, including exposure to testosterone. Benign tumors are the uncontrolled division of cells that form a mass in the prostate. A cancerous tumor is also uncontrolled growth, but in contrast, it invades the surrounding tissues. Not all prostate growths are influenced by testosterone, but many are.
Some treatments for benign prostatic hypertrophy, benign tumors and malignant tumors affect testosterone. For example, finasteride and dutasteride block the enzyme 5-alpha-reductase, preventing it from converting testosterone to DHT. Some cancer medications signal the brain to decrease signalling to the testes, preventing the synthesis of testosterone, and surgical castration is sometimes used as well.
- "Physiology"; Linda S.Costanzo; 4th Ed 2008
- "Harrison's Principles of Internal Medicine"; Anthony S Fauci, et al.; 17th Ed 2008