Chemical agents and peptides affect hair growth

Over the past decade, researchers have investigated the effects of various chemical agents on hair growth using a macaque model of androgenetic alopecia. They found that minoxidil and diazoxide, both hypotensive agents with vasodilatory properties, induced significant hair regrowth when applied topically to bald scalps of macaques. Additionally, the use of a steroid 5 alpha-reductase inhibitor (4MA) in young, non-bald macaques prevented the development of baldness over a 2-year period, unlike in untreated controls. The efficacy of these treatments was assessed using phototrichograms, folliculograms, and measurements of DNA synthesis rates in follicular cells. The treatments primarily stimulated follicular cell proliferation, leading to the enlargement of anagen follicles from vellus to terminal type, or maintaining the size of prebald terminal follicles. Furthermore, a copper binding peptide (PC1031) was found to enlarge follicles on the back skin of fuzzy rats, an effect similar to that of topical minoxidil. The study also explored the potential mechanisms of action of these agents on follicular growth and the role of androgens in follicular epithelial-mesenchymal interactions.