Human blood neutrophil responses to prolonged exercise with and without a thermal clamp

J Appl Physiol (1985). 2008 Jan;104(1):20-6. doi: 10.1152/japplphysiol.00792.2007. Epub 2007 Sep 27.


The purpose of this study was to investigate the effects of prolonged exercise with and without a thermal clamp on neutrophil trafficking, bacterial-stimulated neutrophil degranulation, stress hormones, and cytokine responses. Thirteen healthy male volunteers (means +/- SE: age 21 +/- 1 yr; mass 74.9 +/- 2.1 kg; maximal oxygen uptake 58 +/- 1 ml x kg(-1) x min(-1)) completed four randomly assigned, 2-h water-immersion trials separated by 7 days. Trials were exercise-induced heating (EX-H: water temperature 36 degrees C), exercise with a thermal clamp (EX-C: 24 degrees C), passive heating (PA-H: 38.5 degrees C), and control (CON: 35 degrees C). EX-H and EX-C was comprised of 2 h of deep water running at 58% maximal oxygen uptake. Blood samples were collected at pre-, post-, and 1 h postimmersion. Core body temperature was unaltered on CON, clamped on EX-C (-0.02 degrees C), and rose by 2.23 degrees C and 2.31 degrees C on EX-H and PA-H, respectively. Exercising with a thermal clamp did not blunt the neutrophilia postexercise (EX-C postexercise: 9.6 +/- 1.1 and EX-H postexercise: 9.8 +/- 1.0 x 10(9)/liter). Neutrophil degranulation decreased (P < 0.01) similarly immediately after PA-H (-21%), EX-C, and EX-H (-28%). EX-C blunted the circulating norepinephrine, cortisol, granulocyte-colony stimulating factor, and IL-6 response (P < 0.01) but not the plasma epinephrine and serum growth hormone response. These results show a similar neutrophilia and decrease in neutrophil degranulation after prolonged exercise with and without a thermal clamp. As such, the rise in core body temperature does not appear to mediate neutrophil trafficking and degranulation responses to prolonged exercise. In addition, these results suggest a limited role for cortisol, granulocyte-colony stimulating factor, and IL-6 in the observed neutrophil responses to prolonged exercise.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Body Temperature*
  • Cell Degranulation*
  • Cytokines / blood*
  • Exercise*
  • Granulocyte Colony-Stimulating Factor / blood
  • Hormones / blood*
  • Humans
  • Hydrocortisone / blood
  • Hyperthermia, Induced*
  • Immersion
  • Interleukin-6 / blood
  • Leukocyte Count
  • Male
  • Neutrophils / metabolism*
  • Norepinephrine / blood
  • Time Factors
  • Water


  • Cytokines
  • Hormones
  • IL6 protein, human
  • Interleukin-6
  • Water
  • Granulocyte Colony-Stimulating Factor
  • Hydrocortisone
  • Norepinephrine