17[Beta]-Estradiol and ICI-182780 regulate the hair follicle cycle in mice through an estrogen receptor-[Alpha] pathway

Chanda, Sanjay, C. Lee Robinette, John F. Couse, and Robert C. Smart. 17[Beta]-Estradiol and ICI-182780 regulate the hair follicle cycle in mice through an estrogen receptor-[Alpha] pathway. Am. J. Physiol. Endocrinol. Metab. 278: E202--E210, 2000.--Estradiol ([E.sub.2]) applied topically twice weekly to mouse skin at doses as low as 1 nmol inhibited hair growth by blocking the transition of the hair follicle from the resting phase (telogen) to the growth phase (anagen). In contrast, application of [is less than or equal to] 10 nmol of other steroids produced limited inhibition. Topical treatment with the estrogen receptor (ER) antagonist ICI-182780 reversed the effects of [E.sub.2], and when applied alone, ICI-182780 caused a telogen-to-anagen transition. Both [E.sub.2] and ICI-182780 were highly effective at their site of application but not at distant sites, indicating the direct rather than secondary systemic nature of their effects. Western analysis detected a 65-kDa ER-[Alpha] immunoreactive dermal protein, and Northern analysis revealed the presence of a 6.7-kb ER-[Alpha] mRNA. A ribonuclease protection assay confirmed the presence of ER-[Alpha] transcripts but failed to detect ER-[Beta] transcripts. These findings implicate a skin-specific ER-[Alpha] pathway in the regulation of the hair follicle cycle. skin; hair growth; hormones; androgens