The 5 Alpha-Reductase Isozyme Family: A Review of Basic Biology and Their Role in Human Diseases
Faris Azzouni, Alejandro Godoy, Yun Li, and James Mohler
9.1.2. Newborn-Onset of Puberty
In newborns, 5α-R1 is expressed at the protein level in the liver, skin, scalp [
13] and prostate [
55]. 5α-R2 is expressed in prostate, seminal vesicles, epididymis, liver, and to lesser extent in scalp and skin [
13]. Hepatic expression of 5α-R1 and 2 is present at the protein level (immunoblotting) throughout postnatal life. At approximately 1.5 years, the expression of both proteins is not detected in the skin and scalp until the onset of puberty.
At puberty, only 5α-R1 is reexpressed in the skin and scalp and persists thereafter until 81 years. In the prostate gland, Lunacek et al. reported that both 5α-R1 and 5α-R2 were detectable at the protein level using IHC until approximately 1 year of age. After that, they were detectable at the mRNA level (RT-PCR) until 6 years of age. Thigpen et al. only detected 5α-R2 at the protein level using immunoblotting in prostatic tissue from a 7-year-old male. Since the methods used by this group did not detect 5α-R1 protein in the newborn, juvenile, or adult prostatic tissues, and since other groups detected 5α-R1 at the protein level in fetal and adult benign prostatic tissue, 5α-R1 and 5α-R2 appear to be expressed in the prostate in male fetuses and throughout postnatal life.