title: Time course of cortisol loss in hair segments under immersion in hot water.
abstract: BACKGROUND
  Hair cortisol is supposed to be a good biomarker of chronic stress. Major loss of hair cortisol in long-term exposure to environmental factors affected strongly its proper assessment of chronic stress in human. However, there was no research on time course of hair cortisol loss during the long-term exposure.
  
  
  METHODS
  Hair samples with longer than 1cm in the posterior vertex region were cut as close as possible to the scalp. The 1-cm hair samples were treated by ultraviolet irradiation or immersion in shampoo solution or water immersion at 40, 65 and 80°C. Hair cortisol content was determined with high performance liquid chromatography tandem mass spectrometry.
  
  
  RESULTS
  Ultraviolet irradiation and immersion in shampoo solution and hot water gave rise to the significant cortisol loss in hair. Hair cortisol content was sharply decreased with water immersion duration during initial stage and slowly decreased in the following stage.
  
  
  CONCLUSIONS
  The 2-stage loss process with water immersion duration modeled to some extent time course of hair cortisol loss in long-term exposure to external environments. Cortisol from hair samples closest to the scalp in the posterior vertex could represent more accurately central hypothalamo-pituitary-adrenal activity.
authors: Key Laboratory of Child Development and Learning Science (Southeast University), Ministry of Education, Research Center of Learning Science, Southeast University, Nanjing, China.
authors: Jifeng
authors: J
authors: Li
authors: Qiaozhen
authors: Q
authors: Xie
authors: Wei
authors: W
authors: Gao
authors: Youyun
authors: Y
authors: Xu
authors: Shuang
authors: S
authors: Wang
authors: Huihua
authors: H
authors: Deng
authors: Zuhong
authors: Z
authors: Lu
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D006197:Hair / Q000378:metabolism* / Q000528:radiation effects; D006358:Hot Temperature; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D006920:Hygiene; D007101:Immersion; D008297:Male; D053719:Tandem Mass Spectrometry; D013997:Time Factors; D014466:Ultraviolet Rays; D014867:Water; D055815:Young Adult
chemical_list: D015415:Biomarkers; D014867:Water; D006854:Hydrocortisone