Content of 5-alpha-reductase (type 1 and type 2) mRNA in dermal papillae from the lower abdominal region in women with hirsutism

Androgens influence the growth of terminal hair. The dermal papilla contains androgen receptors and the enzymes 5-alpha-reductase types 1 and 2. Both of these enzymes convert testosterone to the more active androgen, 5-alpha-dihydrotestosterone. The male distribution pattern of terminal hair in females is termed hirsutism. It is most common among women with hyperandrogenism; however, it may also affect patients with normal androgen levels (idiopathic hirsutism). The aim of this study was to assess the expression of 5-alpha-reductase types 1 and 2 mRNA in dermal papillae from the lower abdominal skin in women with hirsutism. The study included 42 subjects, 24 with a diagnosis of polycystic ovary syndrome (PCOS) and 18 with idiopathic hirsutism (IH). In all patients, free serum testosterone was measured. The mean +/- SD concentration of free serum testosterone was 7.2 +/- 5.3 pmol/L in the total group of patients, 10.8 +/- 4.0 pmol/L in patients with PCOS, and 2.5 +/- 1.7 pmol/L in patients with IH. Quantitative analysis was then performed for the mRNA of 5-alpha-reductase types 1 and 2, both of which were found within the dermal papillae from the lower abdominal skin region. The number of mRNA copies/mu g of total RNA for 5-alpha-reductase type 1 was statistically significantly higher than that for type 2 in both groups of examined patients. We also demonstrated a positive correlation between the number of mRNA copies/mu g of total RNA for 5-alpha-reductase types 1 and 2 and the concentration of free serum testosterone in women with PCOS and IH. Considering all patients together, we found a positive correlation between the number of mRNA copies/mu g of total RNA for 5-alpha-reductase type 2 and the concentration of free serum testosterone. There was also a tendency towards a positive correlation between the number of mRNA copies/mu g of total RNA for 5-alpha-reductase type 1 and the concentration of free serum testosterone. The results of our study suggest that testosterone increases expression of 5-alpha-reductase types 1 and 2 in dermal papillae from the lower abdominal region in patients with hirsutism.