Neutrophil degranulation response to 2 hours of exercise in a 30 degrees C environment
Research output: Contribution to journal › Article › peer-review
Standard Standard
In: Aviation Space and Environmental Medicine, Vol. 76, No. 11, 11.2005, p. 1068-73.
Research output: Contribution to journal › Article › peer-review
HarvardHarvard
APA
CBE
MLA
VancouverVancouver
Author
RIS
TY - JOUR
T1 - Neutrophil degranulation response to 2 hours of exercise in a 30 degrees C environment
AU - Laing, Stewart J
AU - Blackwell, Jamie
AU - Gwynne, Dafydd
AU - Walters, Robert
AU - Walsh, Neil P
PY - 2005/11
Y1 - 2005/11
N2 - INTRODUCTION: Evidence supports an interaction between neuro-endocrine responses to exercise and immune responses to exercise. We hypothesized that prolonged exercise in the heat would evoke a greater stress hormone response and a greater decrease in neutrophil degranulation [lipopolysaccharide (LPS)-stimulated elastase release] than when the same exercise was performed in thermoneutral conditions.METHODS: In counterbalanced order and separated by 7 d, 13 male cyclists cycled for 2 h at 62 +/- 3% VO2max (mean +/- SEM), with ad libitum water intake, on one occasion with heat (HOT: 30.3 degrees C, 76% RH) and on another occasion without (CONTROL: 20.4 degrees C, 60% RH). Venous blood samples were collected at pre-, post-, and 2 h post-exercise.RESULTS: Exercising HR, rating of perceived exertion, rectal temperature, corrected body mass loss, and plasma cortisol at post- and 2 h post-exercise were greater during HOT. A marked neutrophilia was evident at post- and 2 h post-exercise with no difference between trials. LPS-stimulated elastase release per neutrophil decreased post-exercise with no difference between trials (pre-exercise: HOT 189 +/- 20 and CONTROL 210 +/- 32; post-exercise: HOT 127 +/- 18 and CONTROL 136 +/- 29 fg x cell(-1)). There was no effect of exercise or trial on neutrophil CD11b expression (neutrophil activation index) or band cell percentage (neutrophil maturity index).CONCLUSIONS: Prolonged exercise results in a decrease in neutrophil degranulation that is unaffected by performing the exercise in hot conditions despite the increase in physiological stress. Additionally, these data suggest that the decrease in neutrophil degranulation after prolonged exercise is not associated with a change in neutrophil activation or maturity as previously suggested.
AB - INTRODUCTION: Evidence supports an interaction between neuro-endocrine responses to exercise and immune responses to exercise. We hypothesized that prolonged exercise in the heat would evoke a greater stress hormone response and a greater decrease in neutrophil degranulation [lipopolysaccharide (LPS)-stimulated elastase release] than when the same exercise was performed in thermoneutral conditions.METHODS: In counterbalanced order and separated by 7 d, 13 male cyclists cycled for 2 h at 62 +/- 3% VO2max (mean +/- SEM), with ad libitum water intake, on one occasion with heat (HOT: 30.3 degrees C, 76% RH) and on another occasion without (CONTROL: 20.4 degrees C, 60% RH). Venous blood samples were collected at pre-, post-, and 2 h post-exercise.RESULTS: Exercising HR, rating of perceived exertion, rectal temperature, corrected body mass loss, and plasma cortisol at post- and 2 h post-exercise were greater during HOT. A marked neutrophilia was evident at post- and 2 h post-exercise with no difference between trials. LPS-stimulated elastase release per neutrophil decreased post-exercise with no difference between trials (pre-exercise: HOT 189 +/- 20 and CONTROL 210 +/- 32; post-exercise: HOT 127 +/- 18 and CONTROL 136 +/- 29 fg x cell(-1)). There was no effect of exercise or trial on neutrophil CD11b expression (neutrophil activation index) or band cell percentage (neutrophil maturity index).CONCLUSIONS: Prolonged exercise results in a decrease in neutrophil degranulation that is unaffected by performing the exercise in hot conditions despite the increase in physiological stress. Additionally, these data suggest that the decrease in neutrophil degranulation after prolonged exercise is not associated with a change in neutrophil activation or maturity as previously suggested.
KW - Adult
KW - Blood Cell Count
KW - Body Temperature
KW - Body Weight
KW - Cell Degranulation
KW - Exercise Test
KW - Heart Rate
KW - Humans
KW - Hydrocortisone
KW - Male
KW - Neutrophils
KW - Pancreatic Elastase
KW - Physical Exertion
KW - Prolactin
KW - Rectum
KW - Temperature
KW - Controlled Clinical Trial
KW - Journal Article
KW - Research Support, Non-U.S. Gov't
M3 - Article
C2 - 16313144
VL - 76
SP - 1068
EP - 1073
JO - Aviation Space and Environmental Medicine
JF - Aviation Space and Environmental Medicine
SN - 0095-6562
IS - 11
ER -