In Vitro Effects of Testosterone, Dihydrotestosterone, and Estradiol on Cell Growth of Human Hair Bulb Papilla Cells and Hair Root Sheath Fibroblasts

The study investigated the effects of testosterone, dihydrotestosterone, and estradiol on the growth of human hair bulb papilla cells and hair root sheath fibroblasts, using samples from 6 healthy male subjects. It was found that dihydrotestosterone and testosterone at concentrations above 30 ng/ml significantly inhibited the growth of both cell types, while lower doses had no effect. Estradiol did not affect growth at concentrations up to 10 ng/ml, but higher concentrations significantly promoted growth. Papilla cells were more sensitive to dihydrotestosterone and testosterone than root sheath fibroblasts, as indicated by growth curves, [3H]thymidine uptake, and cell doubling time.