What does the enzyme 5-alpha-reductase do?
Brief Summary: The enzyme 5-alpha reductase is present in small amounts in muscle and converts testosterone to dihydrotestosterone (DHT). Testosterone affects lean body tissue, muscle size, muscle strength, and sexual function in men.
What type of enzyme is 5-alpha-reductase?
5α-Reductases, also known as 3-oxo-5α-steroid 4-dehydrogenases, are enzymes involved in steroid metabolism. They participate in three metabolic pathways: bile acid biosynthesis, androgen and estrogen metabolism.
What are examples of 5-alpha-reductase inhibitors?
5-alpha-reductase inhibitors are a group of drugs that are used in the treatment of an enlarged prostate gland (benign prostatic hyperplasia) and male pattern hair loss. Drugs in this class are finasteride (marketed as Proscar [finasteride 5 mg] and Propecia [finasteride 1 mg]) and dutasteride (marketed as Avodart).
What is the normal function of 5 A reductase reductase and what does it have to do with this disorder?
With this condition, the testes produce normal amounts of testosterone. Normally, the 5-alpha-reductase enzyme converts testosterone to dihydrotestosterone (DHT), which promotes virilization (masculinization) prior to puberty.
What is the action of 5 alpha reductase inhibitors?
Thus, 5-alpha reductase inhibitors (5-ARIs) effectively reduce the serum and intraprostatic concentration of DHT, causing an involution of prostate tissue. Two 5-ARIs are currently available for the treatment of BPH—finasteride and dutasteride.
How many types of 5-alpha-reductase are there?
The 5-alpha-reductase enzyme exists in two forms: type 1 and type 2. Finasteride inhibits type 2 only, whereas dutasteride inhibits both. Although dutasteride provides greater suppression of dihydrotestosterone, it is not known if this provides a significant advantage clinically.
Is 5-alpha-reductase a hormone?
The SRD5A2 gene provides instructions for making an enzyme called steroid 5-alpha reductase 2. This enzyme is involved in processing androgens, which are hormones that direct male sexual development. Specifically, the enzyme is responsible for a chemical reaction that converts the hormone testosterone to DHT.
What are 5-ARI drugs?
Drugs in the 5-ARI class are finasteride and dutasteride. These drugs are marketed under the brand-names Proscar, Propecia, Avodart, and Jalyn. Finasteride is available in two different strengths: Proscar 5 mg tablets and Propecia 1 mg tablets.
What increased 5-alpha-reductase?
In women, increased 5α-reductase activity has been associated with idiopathic hirsutism (28), androgenic alopecia (29), and acne (30). Increased 5α-reductase activity in specific tissues, such as the skin (31) and ovary (21), has been reported in women with PCOS.
What is the structure of 5α-reductase?
5α-Reductase is a membrane bound enzyme that catalyzes the NADPH dependent reduction of double bonds in steroid substrates to increase potency. The crystal structure of a homolog of 5α-reductase isoenzymes 1 and 2 has been found in Proteobacteria (proteobacteria 5α-reductase).
What reactions are catalyzed by 5α-reductase?
The following reactions are known to be catalyzed by 5α-reductase: 5α-Reductase is a membrane bound enzyme that catalyzes the NADPH dependent reduction of double bonds in steroid substrates to increase potency. The crystal structure of a homolog of 5α-reductase isoenzymes 1 and 2 has been found in Proteobacteria (proteobacteria 5α-reductase).
What is 5-alpha reductase?
In another metabolic pathway, 5-alpha reductase reduces testosterone to dihydrotestosterone. The highest production of 5-alpha-reductase mRNA was found during puberty (Shidaifat, 2009). Testosterone conversion to 5-alpha dihydrotestosterone in target cells is a widespread activation mechanism that amplifies the androgen signal.
What causes 5 alpha reductase type 2 deficiency?
In 5 alpha reductase type 2 deficient males, the type 1 isoenzyme is thought to be responsible for their virilization at puberty. Impaired 5α-reductase 2 activity can result from mutations in the underlying SRD5A2 gene.