Concentration of cortisol in human hair under rest and pain conditions

C.F. Sharpley, K. Kauter and J. McFarlane, Department of Physiology, School of Science and Technology, University of New England, Armidale, NSW 2351, Australia.

Four investigations were conducted into the concentration and responsivity of cortisol in adult human hair. Concentration across body sites (n = 10 males) varied significantly, with highest values in the arms, followed by legs, with the scalp being lowest. However, concentrations within-shaft from a single site were significantly correlated in longer female (n = 12) hair. Two studies of concentration changes following 1 min immersion in ice water (0°C to 4°C) were also conducted. The first study (n = 3 males) showed immediate, brief and localized increases in cortisol from hair on the immersed forearm but not from hair on the opposite lower leg. The second study (n = 5 males) showed further localization of hair cortisol changes along the forearm, with independent responses being observed in areas only 250mm apart. These results are considered within a model of localized anti-inflammatory hair cortisol responses to trauma and add to our knowledge of the peripheral cortisol synthesis system in human hair.