Progenitor cells are mobilized by acute physiological stress but not beta-adrenergic receptor agonist infusion

Research output: Contribution to journalArticlepeer-review


  • Natalie Riddell
  • Victoria Burns
  • Kate M Edwards
  • Laura S Redwine
  • Suzi Hong
  • Jack C Bui
  • Johannes C Fischer
  • Paul J Mills


Stimuli that activate the sympathetic nervous system, such as acute psychological stress, rapidly invoke a robust mobilization of lymphocytes into the circulation. Experimental animal studies suggest that bone marrow-derived progenitor cells (PCs) also mobilize in response to sympathetic stimulation. Here we tested the effects of acute psychological stress and brief pharmacological β-adrenergic (βAR) stimulation on peripheral PC numbers in humans.

In two studies, we investigated PC mobilization in response to an acute speech task (n = 26) and βAR-agonist (isoproterenol) infusion (n = 20). A subset of 8 participants also underwent the infusion protocol with concomitant administration of the βAR-antagonist propranolol. Flow cytometry was used to enumerate lymphocyte subsets, total progenitor cells, total haematopoietic stem cells (HSC), early HSC (multi-lineage potential), late HSC (lineage committed), and endothelial PCs (EPCs).

Both psychological stress and βAR-agonist infusion caused the expected mobilization of total monocytes and lymphocytes and CD8+ T lymphocytes. Psychological stress also induced a modest, but significant, increase in total PCs, HSCs, and EPC numbers in peripheral blood. However, infusion of a βAR-agonist did not result in a significant change in circulating PCs.

PCs are rapidly mobilized by psychological stress via mechanisms independent of βAR-stimulation, although the findings do not exclude βAR-stimulation as a possible cofactor. Considering the clinical and physiological relevance, further research into the mechanisms involved in stress-induced PC mobilization seems warranted.


Original languageEnglish
Pages (from-to)49-53
Number of pages5
JournalBrain, Behaviour, and Immunity
Early online date6 Mar 2015
Publication statusPublished - Oct 2015


  • Progenitor cells, Mobilization, Psychological stress, βAR-stimulation, Adrenergic