Acute carbon dioxide exposure in healthy adults: Evaluation of a novel means of investigating the stress response

Joey Kaye, F. Buchanan, A. Kendrick, P. Johnson, C. Lowry, J. Bailey, D. Nutt, S. Lightman

Research output: Contribution to journalReview article

87 Scopus citations


Acute hypercapnia was studied to assess its potential as a noninvasive and simple test for evoking neuroendocrine, cardiovascular and psychological responses to stress in man. A single breath of four concentrations of carbon dioxide (CO2), 5%, 25%, 35% and 50%, was administered to nine healthy volunteers in a randomized, single-blind fashion. Although no adverse effects occurred, most subjects were unable to take a full inspired vital capacity breath of 50% CO2. In response to the remaining exposures, subjective and somatic symptoms of anxiety increased in a dose-dependent manner. Unlike 5% and 25% CO 2, 35% CO2 stimulated significant adrenocorticotropic hormone and noradrenaline release at 2 min and cortisol and prolactin release at 15 min following inhalation. This same dose also provoked a significant bradycardia that was followed by an acute pressor response. No significant habituation of psychological, hypothalamic-pituitary-adrenal (HPA) or cardiovascular responses following 35% CO2 was seen when this dose was repeated after 1 week. A single breath of 35% CO2 safely and reliably produced sympathetic and HPA axis activation and should prove a useful addition to currently available laboratory tests of the human stress response.

Original languageEnglish (US)
Pages (from-to)256-264
Number of pages9
JournalJournal of Neuroendocrinology
Issue number3
StatePublished - Mar 2004


  • Carbon dioxide
  • Catecholamines
  • Cortisol
  • HPA axis
  • Stress

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology
  • Endocrine and Autonomic Systems
  • Cellular and Molecular Neuroscience

Fingerprint Dive into the research topics of 'Acute carbon dioxide exposure in healthy adults: Evaluation of a novel means of investigating the stress response'. Together they form a unique fingerprint.

  • Cite this