Immunohistochemical Localization of Types 1 and 2 5α-Reductase in Human Scalp
September 1999
in “
British Journal of Dermatology
”
TLDR The study found that two enzymes linked to hair loss are located in different parts of the scalp, supporting a common treatment's effectiveness.
The 1999 study investigated the distribution of 5α-reductase isozymes in the human scalp, with a focus on their role in androgenetic alopecia. It found that type 1 5α-reductase (5αR1) is predominantly located in sebaceous glands, while type 2 5α-reductase (5αR2) is localized within hair follicles, specifically in the inner layer of the outer root sheath and the infundibular region. The presence of 5αR2 in hair follicles supports the effectiveness of finasteride, a 5αR2 inhibitor, in treating male pattern hair loss by acting locally at the follicular level. The study did not specify the number of participants but focused on the cellular and molecular localization of these enzymes.