Safer J D, Fraser L M, Ray S, Holick M F
Department of Medicine, Boston University School of Medicine, Massachusetts 02118, USA.
Thyroid. 2001 Aug;11(8):717-24. doi: 10.1089/10507250152484547.
The skin is a classic target tissue for thyroid hormone action. Although the histology of skin in hypothyroid states is well documented, the literature contains little assessment of skin in thyrotoxic states. In light of the paucity of information on skin under the influence of excess thyroid hormone, we investigated the direct effect of thyroid hormone on skin. Triiodothyronine (T3) was applied topically daily in liposomes to SKH-1 hairless mice for 7 days and to CD rats for 2 weeks. There was a dose-dependent increase in epidermal proliferation, dermal thickening, and hair growth in T3-treated animals. Mice that received 3.8 microg of T3 had 42% more hairs per millimeter than controls (p < 0.01), hair length that was 1,180% longer (p < 0.001), 49% greater epidermal 3H-thymidine incorporation (p < 0.01), and 80% more 5-bromo-2'-deoxyuridine (BrdU) stained cells (p < 0.05). Rats receiving 12.8 microg T3 had 48% greater dermal thickness than controls (p < 0.001), 26% greater epidermal thickness (p < 0.001), 85% more hairs per millimeter (p < 0.005), and 130% greater 3H-thymidine incorporation into the epidermis (p < 0.01). Thus, topically applied thyroid hormone has dramatic effects on both skin and hair growth. These observations offer a new strategy for developing thyroid hormone and its analogues for treating disorders of skin and hair growth.
皮肤是甲状腺激素作用的典型靶组织。虽然甲状腺功能减退状态下皮肤的组织学已有充分记载，但文献中对甲状腺毒症状态下的皮肤评估较少。鉴于关于甲状腺激素过量影响下皮肤的信息匮乏，我们研究了甲状腺激素对皮肤的直接作用。将三碘甲状腺原氨酸（T3）每日局部应用于脂质体中，作用于SKH - 1无毛小鼠7天，作用于CD大鼠2周。在T3处理的动物中，表皮增殖、真皮增厚和毛发生长呈剂量依赖性增加。接受3.8微克T3的小鼠每毫米毛发数量比对照组多42%（p < 0.01），毛发长度长1180%（p < 0.001），表皮3H - 胸苷掺入量高49%（p < 0.01），5 - 溴 - 2'-脱氧尿苷（BrdU）染色细胞多80%（p < 0.05）。接受12.8微克T3的大鼠真皮厚度比对照组厚48%（p < 0.001），表皮厚度厚26%（p < 0.001），每毫米毛发数量多85%（p < 0.005），表皮3H - 胸苷掺入量高130%（p < 0.01）。因此，局部应用甲状腺激素对皮肤和毛发生长有显著影响。这些观察结果为开发甲状腺激素及其类似物用于治疗皮肤和毛发生长紊乱提供了新策略。
