title: Role of 5α-reductase inhibitors in benign prostatic diseases.
abstract: Testosterone is the most abundant androgen in serum. Intracellularly, testosterone is converted to dihydrotestosterone, the preferred ligand for androgen receptor transactivation, by the enzyme 5α-reductase. Three 5α-reductase isozymes have been discovered and they are expressed ubiquitously in human tissues. Testosterone and dihydrotestosterone have different but complimentary functions. Dihydrotestosterone has 2-5 times higher binding affinity for the androgen receptor than testosterone, and 10-fold higher potency of inducing androgen receptor signaling than testosterone. The role of dihydrotestosterone was discovered after the description of 5α-reductase type 2 deficiency in 1974, where affected males have normal internal but ambiguous external genitalia. Neither BPH nor prostate cancer has been reported in these patients. Currently, two 5α-reductase inhibitors are available for clinical use. This review will discuss the important clinical trials of 5α-reductase inhibitors in the treatment of benign prostatic diseases.
authors.affiliation: Department of Urology, Roswell Park Cancer Institute, Buffalo, NY 14263, USA. faris.azzouni@roswellpark.org
authors.forename: F
authors.initials: F
authors.lastname: Azzouni
authors.forename: J
authors.initials: J
authors.lastname: Mohler
mesh_terms: D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000378:metabolism; D058891:5-alpha Reductase Inhibitors / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D017410:Practice Guidelines as Topic; D011470:Prostatic Hyperplasia / Q000188:drug therapy* / Q000201:enzymology / Q000517:prevention & control; D011472:Prostatitis / Q000188:drug therapy* / Q000201:enzymology
chemical_list: D058891:5-alpha Reductase Inhibitors; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase