- 5-alpha reductase
protein
Name = steroid-5-alpha-reductase, alpha polypeptide 1
caption =
width =
HGNCid = 11284
Symbol =SRD5A1
AltSymbols =
EntrezGene = 6715
OMIM = 184753
RefSeq = NM_001047
UniProt = P18405
PDB =
ECnumber = 1.3.99.5
Chromosome = 5
Arm = p
Band = 15
LocusSupplementaryData = protein
Name = steroid-5-alpha-reductase, alpha polypeptide 2
caption =
width =
HGNCid = 11285
Symbol =SRD5A2
AltSymbols =
EntrezGene = 6716
OMIM = 607306
RefSeq = NM_000348
UniProt = P31213
PDB =
ECnumber = 1.3.99.5
Chromosome = 2
Arm = p
Band = 23
LocusSupplementaryData =5-alpha reductase is an enzyme that converts
testosterone , the malesex hormone , into the more potentdihydrotestosterone :Note the major difference -- the Δ4,5 double-bond on the A (leftmost) ring. (The other differences between the diagrams are unrelated to chemical structure.)
There are two
isoenzyme s, steroid 5-alpha reductase 1 and 2 (SRD5A1 and SRD5A2). The second isoenzyme is deficient in5-alpha-reductase deficiency which leads to a form ofintersexual ism.Production and inhibition
The enzyme is produced only in specific tissues of the male human body, namely the
skin ,seminal vesicles ,prostate andepididymis .Inhibition of 5-alpha reductase results in decreased production of DHT, increased levels of testosterone and possibly increased levels of estradiol.
Gynecomastia is a possible side effect of 5-alpha reductase inhibition.Pharmacology
5-alpha-reductase inhibitor drugs are used inbenign prostatic hyperplasia ,prostate cancer andbaldness .Finasteride inhibits the function of only one of the isoenzymes (type 2), whiledutasteride inhibits both forms.External
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