A Naito1, T Sato, T Matsumoto, K Takeyama, T Yoshino, S Kato, M Ohdera. 1. Biological Science Research Laboratories, Research and Development Headquarters, LION Corporation, 100 Tajima, Odawara, Kanagawa 256-0811, Japan. a-naito@lion.co.jp
Abstract
BACKGROUND: Androgens cause regression of human hair follicles in the parietofrontal scalp, but the precise mechanisms by which they do so are unknown. Although many investigators have elucidated the effect of androgens on hair growth by using rodents and other animals, some of the evidence is conflicting. OBJECTIVES: To investigate the effect of androgens on mouse hair regrowth and hair cycle by using androgen receptor knockout (ARKO) mice. Methods We examined the effects of dihydrotestosterone (DHT) on hair regrowth by using ARKO mice and wild-type (WT) littermates, compared the hair cycles in ARKO mice and WT littermates by histology and histomorphometry, and measured hair length and thickness in ARKO mice and WT littermates. RESULTS: DHT inhibited the hair regrowth of WT mice but not that of their ARKO littermates. The anagen phase in the second hair cycle was longer in ARKO mice than in their WT littermates. The hair of ARKO mice was longer and thicker than that of their WT littermates. CONCLUSIONS: Androgens inhibit hair growth in mice, and this inhibition might be caused by androgen-androgen receptor signals.
BACKGROUND: Androgens cause regression of human hair follicles in the parietofrontal scalp, but the precise mechanisms by which they do so are unknown. Although many investigators have elucidated the effect of androgens on hair growth by using rodents and other animals, some of the evidence is conflicting. OBJECTIVES: To investigate the effect of androgens on mouse hair regrowth and hair cycle by using androgen receptor knockout (ARKO) mice. Methods We examined the effects of dihydrotestosterone (DHT) on hair regrowth by using ARKOmice and wild-type (WT) littermates, compared the hair cycles in ARKOmice and WT littermates by histology and histomorphometry, and measured hair length and thickness in ARKOmice and WT littermates. RESULTS:DHT inhibited the hair regrowth of WT mice but not that of their ARKO littermates. The anagen phase in the second hair cycle was longer in ARKOmice than in their WT littermates. The hair of ARKOmice was longer and thicker than that of their WT littermates. CONCLUSIONS: Androgens inhibit hair growth in mice, and this inhibition might be caused by androgen-androgen receptor signals.
Authors: Denny L Cottle; Kai Kretzschmar; Pawel J Schweiger; Sven R Quist; Harald P Gollnick; Ken Natsuga; Satoru Aoyagi; Fiona M Watt Journal: Cell Rep Date: 2013-02-09 Impact factor: 9.423