Endocrine Abstracts

Oestrogens have important modulatory effects on the skin and the hair follicle. Although they inhibit hair growth in animal models, their effect on human hair growth is less clear. Therefore, we have investigated the effect of oestrogenic compounds on human hair growth in vitro using a whole follicle assay system.

Individual microdissected hair follicles from female temporal/occipital scalp (n=6, age range 49–69 mean age 54.67yrs) were incubated individually in phenol red-free William’s E medium supplemented with L-glutamine, penicillin, streptomycin and 5 mM glucose. A minimum of six follicles from each patient was incubated with one of the following; vehicle control (0.0001% alcohol), 10 nM 17β-oestradiol, 10 nM 17α-oestradiol, 1μM genestein, 100 nM tamoxifen or 10 nM 17β-oestradiol plus 100 nM tamoxifen for 7 days, which a media change every second day. Every 24 hours, the increase in follicle length was measured using an inverted microscope fitted with an eyepiece measuring graticule.

Follicles in each group exhibited linear growth over seven days and exhibited a similar morphology. Follicles incubated with 17α-oestradiol grew at a similar rate to the control group. However, follicles incubated with 17β-oestradiol grew at a significantly (p<0.05) slower rate than the control group. Tamoxifen alone had no effect on hair growth, but inhibited the effect of 17β-oestradiol. Follicles incubated with the phytoestrogen, genestein also grew at a significantly slower rate (p<0.05) than the control group.

These results demonstrate that the human hair follicle has the necessary machinery to respond to oestrogenic compounds in vitro in a selective manner. 17β-oestradiol inhibits human hair growth in vitro, which is negated by tamoxifen, supporting the regulation of human hair growth via an oestrogen receptor. Furthermore, a similar inhibition of growth in the presence of the phytoestrogen, genestein suggests that oestrogens may modulate human hair follicle growth via ERβ.