title: Acute Stress-Induced Changes in Follicular Dermal Papilla Cells and Mobilization of Mast Cells: Implications for Hair Growth.
abstract: BACKGROUND
  Stress is a known cause of hair loss in many species.
  
  
  OBJECTIVE
  In this study, we investigated the role of acute stress on hair growth using a rat model.
  
  
  METHODS
  Rats were immobilized for 24 hours and blood samples, and skin biopsies were taken. The effect of stress-serum on thein vitroproliferation of rat and human dermal papilla cells (hDPCs), as well as serum cortisol and corticotropin-releasing hormone levels, were measured. Mast cell staining was performed on the biopsied tissue. In addition, Western blot and quantitative real time polymerase chain reaction were used to assess mast cell tryptase and cytokine expression, respectively in rat skin biopsies.
  
  
  RESULTS
  Stress-serum treatment reduced significantly the number of viable hDPCs and arrested the cell cycle in the G1 phase, compared to serum from unrestrained rats (p<0.05, respectively). Moreover, restrained rats had significantly higher levels of cortisol in serum than unrestrained rats (p<0.01). Acute stress serum increased mast cell numbers and mast cell tryptase expression, as well as inducing interleukin (IL)-6 and IL-1β up-regulation.
  
  
  CONCLUSIONS
  These results suggest that acute stress also has an inhibitory effect on hair growth via cortisol release in addition to substance P-mast cell pathway.
authors.affiliation: Department of Dermatology, Dongguk University Ilsan Hospital, Goyang, Korea.
authors.forename: Hyoseung
authors.initials: H
authors.lastname: Shin
authors.affiliation: Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea.; Laboratory of Cutaneous Aging and Hair Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.; Institute of Human-Environment Interface Biology, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Soon-Jin
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea.; Laboratory of Cutaneous Aging and Hair Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.; Institute of Human-Environment Interface Biology, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: A-Ri
authors.initials: AR
authors.lastname: Cho
authors.affiliation: Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea.; Laboratory of Cutaneous Aging and Hair Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.; Institute of Human-Environment Interface Biology, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Dong Young
authors.initials: DY
authors.lastname: Kim
authors.affiliation: Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea.; Laboratory of Cutaneous Aging and Hair Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.; Institute of Human-Environment Interface Biology, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Kyu Han
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Dermatology, Seoul National University College of Medicine, Seoul, Korea.; Laboratory of Cutaneous Aging and Hair Research, Biomedical Research Institute, Seoul National University Hospital, Seoul, Korea.; Institute of Human-Environment Interface Biology, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ohsang
authors.initials: O
authors.lastname: Kwon
keywords: Cortisol; Dermal papilla; Hair; Mast cells; Rats; Stress; physiological