Topical 17-beta-estradiol (E2) regulates the hair cycle, hair shaft differentiation, and sebum production. Vitamin A also regulates sebum production. Vitamin A metabolism proteins localized to the pilosebaceous unit (PSU; hair follicle and sebaceous gland); and were regulated by E2 in other tissues. This study tests the hypothesis that E2 also regulates vitamin A metabolism in the PSU. First, aromatase and estrogen receptors localized to similar sites as retinoid metabolism proteins during mid-anagen. Next, female and male wax stripped C57BL/6J mice were topically treated with E2, the estrogen receptor antagonist ICI 182,780 (ICI), letrozole, E2 plus letrozole, or vehicle control (acetone) during mid-anagen. E2 or one of its inhibitors regulated most of the vitamin A metabolism genes and proteins examined in a sex-dependent manner. Most components were higher in females and reduced with ICI in females. ICI reductions occurred in the premedulla, sebaceous gland, and epidermis. Reduced E2 also reduced RA receptors in the sebaceous gland and bulge in females. However, reduced E2 increased the number of retinal dehydrogenase 2 positive hair follicle associated dermal dendritic cells in males. These results suggest that estrogen regulates vitamin A metabolism in the skin. Interactions between E2 and vitamin A have implications in acne treatment, hair loss, and skin immunity.

外用 17-β-雌二醇 (E2) 调节毛发周期、毛干分化和皮脂产生。维生素 A 还可以调节皮脂的产生。维生素 A 代谢蛋白定位于毛囊皮脂腺单位（PSU；毛囊和皮脂腺）；并在其他组织中受到 E2 的调节。这项研究检验了 E2 还调节 PSU 中维生素 A 代谢的假设。首先，在生长期中期，芳香酶和雌激素受体定位于与类视黄醇代谢蛋白相似的位点。接下来，雌性和雄性去蜡 C57BL/6J 小鼠在生长期中期用 E2、雌激素受体拮抗剂 ICI 182,780 (ICI)、来曲唑、E2 加来曲唑或载体对照（丙酮）进行局部治疗。 E2 或其抑制剂之一以性别依赖性方式调节大多数维生素 A 代谢基因和蛋白质。大多数成分在女性中较高，并且随着女性 ICI 的增加而降低。 ICI 减少发生在前髓质、皮脂腺和表皮。 E2 减少还会减少皮脂腺中的 RA 受体和女性的肿胀。然而，E2 减少会增加男性视网膜脱氢酶 2 阳性毛囊相关真皮树突细胞的数量。这些结果表明雌激素调节皮肤中的维生素 A 代谢。 E2 和维生素 A 之间的相互作用对痤疮治疗、脱发和皮肤免疫力具有影响。