title: Energetics of stress: linking plasma cortisol levels to metabolic rate in mammals.
abstract: Physiological stress may result in short-term benefits to organismal performance, but also long-term costs to health or longevity. Yet, we lack an understanding of the variation in stress hormone levels (i.e. glucocorticoids) that exist within and across species. Here, we present comparative analyses that link the primary stress hormone in most mammals (i.e. cortisol) to metabolic rate. We show that baseline concentrations of plasma cortisol vary with mass-specific metabolic rate among cortisol-dominant mammals, and both baseline and elevated concentrations scale predictably with body mass. The results quantitatively link a classical measure of physiological stress to whole-organism energetics, providing a point of departure for cross-species comparisons of stress levels among mammals.
authors.affiliation: School of Natural Resources and Environment, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Catherine G
authors.initials: CG
authors.lastname: Haase
authors.affiliation: Department of Biology, University of North Georgia, Dahlonega, GA 30597, USA.
authors.forename: Andrea K
authors.initials: AK
authors.lastname: Long
authors.affiliation: Department of Biology, University of Florida, Gainesville, FL 32611, USA gillooly@ufl.edu.
authors.forename: James F
authors.initials: JF
authors.lastname: Gillooly
mesh_terms: D000818:Animals; D001481:Basal Metabolism / Q000502:physiology*; D001499:Bayes Theorem; D001835:Body Weight; D005260:Female; D006854:Hydrocortisone / Q000097:blood*; D016014:Linear Models; D008297:Male; D008322:Mammals / Q000502:physiology*; D010802:Phylogeny; D013312:Stress, Physiological
chemical_list: D006854:Hydrocortisone
keywords: allometry; metabolism; scaling; stressor