Hair Loss

J Clin Endocrinol Metab. 1987 Jul;65(1):188-93.

The effects of a 5 alpha-reductase inhibitor and antiandrogen, 4-MA, on the development of baldness in the stumptail macaque.
Rittmaster RS, et al

We used a model of male-pattern baldness to test the efficacy of a topically applied 5 alpha-reductase inhibitor and antiandrogen (4-MA) in the prevention of baldness. Six periadolescent stumptail macaques were given daily topical applications of either 4-MA in dimethylsulfoxide or dimethylsulfoxide alone for 27 months. The three control monkeys developed varying degrees of baldness, while the three 4-MA-treated monkeys retained their juvenile pattern of hair regrowth. snip… We conclude that topical 4-MA can prevent the development of baldness in the stumptail macaque, a primate model of androgen-dependent baldness.

Eur J Dermatol. 2001;11:195.

Influence of estrogens on the androgen metabolism in different subunits of human hair follicles.

Niiyama S,
The molecular pathways involved in estrogen-mediated induction of hair regrowth in male pattern hair loss are unknown. Some authors found that estradiol inhibited 5 alpha-activity and therefore we addressed the question whether 17alpha- or 17beta-E are able to modulate the activity of 5alpha-R, etc. in hair follicles. Scalp biopsies from volunteers were taken and from each biopsy root sheaths, connective tissue sheaths and dermal papillae were dissected and incubated in the presence of 3H-testosterone (T) and, in addition, either 17alpha-E, 17beta-E, progesterone or finasteride for up to 48 hrs. Then, analysis of culture supernatants was performed to detect T-metabolites. At the tested concentrations, finasteride was found to be a major inhibitor of dihydrotestosterone (DHT) formation. Even 1 nM finasteride inhibited DHT synthesis in DP by 86% and 1 nM progesterone by 75%. Estrogens were less able to inhibit the synthesis of DHT in DP (e.g. 100 nM 17alpha-E: 20%; 100 nM 17beta-E: 60%). snip…

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