Exercise-induced alterations in natural killer cell number and function.
To study the effects of exercise on natural killer (NK) cell number and activity (NKCA) healthy male (n = 32) and female (n = 32) subjects were randomly assigned to an exercise or control condition. Exercise involved a continuous incremental protocol consisting of cycling for three periods of 6 min at work rates corresponding to 55%, 70% and 85% peak oxygen uptake (VO2peak). Blood samples were drawn at baseline, at 6 min, 12 min and 18 min during exercise, and at 2 h following completion of exercise. Relative to both baseline and control conditions, exercise resulted in an increase in the number of circulating lymphocytes. The proportion of T cells (CD3+) and B cells (CD19+) significantly decreased, and NK cells (CD3-CD16+CD56+) increased throughout exercise. NKCA increased (P < 0.001) during the initial 6 min of exercise with no further changes observed, despite increases (P < 0.001) in the number and proportion of circulating NK cells during exercise at 70% and 85% VO2peak. Plasma epinephrine and norepinephrine increased (P < 0.001) above baseline at 12 min and 18 min. The changes in NK cell number and function were independent of gender. The results indicate that short-duration low-intensity exercise can significantly increase NK cell number and activity. However, alterations in NK cell number are not accompanied by changes of a similar magnitude in NKCA.
Department of Pathology, University of Pittsburgh Medical Center, PA 15213-2582, USA.
N M
NM
Moyna
G R
GR
Acker
K M
KM
Weber
J R
JR
Fulton
R J
RJ
Robertson
F L
FL
Goss
B S
BS
Rabin
D000328:Adult; D001402:B-Lymphocytes / Q000502:physiology; D004837:Epinephrine / Q000097:blood; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural / Q000502:physiology*; D018655:Lymphocyte Count; D008297:Male; D009638:Norepinephrine / Q000097:blood; D005082:Physical Exertion / Q000502:physiology; D013601:T-Lymphocytes / Q000502:physiology
D009638:Norepinephrine; D004837:Epinephrine