|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Wastl Human Peformance Laboratory, Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana, USA
* To whom correspondence should be addressed. E-mail: bkmcfarlin{at}att.net.
Introduction/purpose. The purpose of this study was to evaluate the effect of high-intensity endurance exercise and carbohydrate consumption on in vitro responsiveness of natural killer (NK) to IL-2 (2.5 U.mL-1 for 24-h). Methods. Thirteen male subjects (18-26 years old; VO2peak = 59.79±5.13 mL.kg-1.mL-1) were recruited to complete two 1-h (75-80% VO2peak) cycling trials in a random counterbalanced order: carbohydrate (CHO) and placebo (PLA). Venous blood samples were collected before (PRE), immediately (POST), 2-h (2H), and 4-h (4H) after exercise. All resting samples were taken following 15 min of seated rest. NK (CD3-/56+), activated NK (CD3-/56+/69+), helper T-cell (Th, CD3+/4+), and cytotoxic T-cell (Tc, CD3+/8+) number were measured using flow cytometry. NK cell activity (NKCA) was determined using both a 51Cr release assay (NKCA-51) and activated NK cell number (NKCA-69). Results. Immune system variables were not different between CHO & PLA; with the exception of NK cell responsiveness to IL-2, where POST (116.2%) and 4H (48.4%) was significantly greater in CHO (p<0.05). NK, Th, and Tc were significantly higher POST (40.7%, 102.7%, 82.0%) and lower at 2H (-51.9%, -53.3%, -53.2%) than PRE (time effect). 4H was not different than PRE for NK, Th, and Tc. NKCA was significantly lower 2H (NKCA-51, NKCA-69) and 4H (NKCA-69) than PRE. Conclusion. CHO consumption during exercise did not prevent disruptions in unstimulated immune system function, but it did enhance NK responsiveness to IL-2.
This article has been cited by other articles:
![]() |
M. G. Flynn, B. K. McFarlin, and M. M. Markofski State of the Art Reviews: The Anti-Inflammatory Actions of Exercise Training American Journal of Lifestyle Medicine, May 1, 2007; 1(3): 220 - 235. [Abstract] [PDF] |
||||
![]() |
B. W. Timmons, M. A. Tarnopolsky, and O. Bar-Or Sex-based effects on the distribution of NK cell subsets in response to exercise and carbohydrate intake in adolescents J Appl Physiol, May 1, 2006; 100(5): 1513 - 1519. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. K. McFarlin, M. G. Flynn, W. W. Campbell, B. A. Craig, J. P. Robinson, L. K. Stewart, K. L. Timmerman, and P. M. Coen Physical activity status, but not age, influences inflammatory biomarkers and toll-like receptor 4. J. Gerontol. A Biol. Sci. Med. Sci., April 1, 2006; 61(4): 388 - 393. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. K. McFarlin, M. G. Flynn, M. D. Phillips, L. K. Stewart, and K. L. Timmerman Chronic Resistance Exercise Training Improves Natural Killer Cell Activity in Older Women J. Gerontol. A Biol. Sci. Med. Sci., October 1, 2005; 60(10): 1315 - 1318. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |