Effects of 17-β-Estradiol and ICI 182 780 on Hair Growth in Various Strains of Mice

The study from 1999 examined the impact of 17-β-Estradiol and ICI 182 780 on hair growth in female and male mice across different strains (C57BL/6, C3H, and CD-1) with 5-6 mice per group. Topical application of 17-β-Estradiol inhibited hair growth in females and males, while ICI 182 780 promoted hair regrowth and accelerated the transition from telogen to anagen phase in both sexes and all strains. Intraperitoneal administration of 17-β-Estradiol did not inhibit hair growth, suggesting its effects are localized to the skin. Notably, 17-α-Estradiol inhibited hair growth in male mice but not in females, indicating a sex-specific response. The study concluded that the effects of these compounds on hair growth are consistent across mouse strains and are likely due to direct action on the skin, with implications for understanding human hair growth. Further research is needed to explore the relevance to humans.