title: Influence of external factors on hair cortisol concentrations.
abstract: Measuring hair cortisol has attracted interest as a long term parameter for chronic stress evaluation. However, some studies support the hypothesis that locally produced cortisol, originating from the hair follicle or skin cells, affects concentrations in the hair. In an animal model the influence of different treatments (extensive brushing, administration of a hyperemising fluid that enhances blood circulation or a synthetic glucocorticoid) on the local cortisol production of hair was evaluated. Therefore eight sheep were sheared and the area of the skin surface of the back was quartered, with three quarters being daily subjected to a certain treatment and one quarter remaining untreated. The skin areas were sheared again after three weeks and cortisol concentrations of all wool samples were determined by immunoassay. Systemic cortisol concentrations were additionally monitored with faecal samples, indicating a significant decline in concentrations of glucocorticoid metabolites between week 1 and 2 or 3, respectively. We found no significant difference in hair cortisol concentrations between fields before treatment (p=0.310). Comparing matched fields before and after treatment, we found no significant differences in wool cortisol concentrations for fields treated with hyperemising fluid as well as for the control fields (p=0.329, p=0.097). Hairs exposed to either extensive brushing or dexamethasone fluid had significantly higher immunoreactive cortisol concentrations after three weeks of treatment (p=0.016, p=0.01). We therefore advise cautious interpretation when measuring hair cortisol concentrations as a parameter for chronic stress, because external factors may have a significant influence on the results.
authors.affiliation: Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department for Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria. Electronic address: theresa@salaberger.at.
authors.forename: Theresa
authors.initials: T
authors.lastname: Salaberger
authors.affiliation: Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department for Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
authors.forename: Marlon
authors.initials: M
authors.lastname: Millard
authors.affiliation: Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department for Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
authors.forename: Samy El
authors.initials: SE
authors.lastname: Makarem
authors.affiliation: Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department for Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
authors.forename: Erich
authors.initials: E
authors.lastname: Möstl
authors.affiliation: Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department for Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
authors.forename: Viktoria
authors.initials: V
authors.lastname: Grünberger
authors.affiliation: University Clinic for Ruminants, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
authors.forename: Reinhild
authors.initials: R
authors.lastname: Krametter-Frötscher
authors.affiliation: University Clinic for Ruminants, Department of Farm Animal and Public Health in Veterinary Medicine, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wittek
authors.affiliation: Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department for Biomedical Sciences, University of Veterinary Medicine Vienna, Veterinärplatz 1, 1210 Vienna, Austria.
authors.forename: Rupert
authors.initials: R
authors.lastname: Palme
mesh_terms: D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology; D004777:Environment; D005243:Feces / Q000737:chemistry; D005260:Female; D005938:Glucocorticoids / Q000378:metabolism; D006197:Hair / Q000737:chemistry / Q000378:metabolism*; D006854:Hydrocortisone / Q000032:analysis / Q000378:metabolism*; D008297:Male; D012756:Sheep; D012867:Skin / Q000737:chemistry / Q000378:metabolism; D013312:Stress, Physiological / Q000502:physiology*; D013315:Stress, Psychological / Q000378:metabolism*
chemical_list: D005938:Glucocorticoids; D003907:Dexamethasone; D006854:Hydrocortisone
keywords: Cortisol; Hair; Influence; Local production; Non-invasive stress monitoring; Wool