Four weeks of acupuncture does not alter natural killer cell response to exercise

Exercise may suppress natural killer cell activity (NKCA) for up to 24-h, creating an "open window" during which an individual may be more likely to get sick. Previous research has shown that acupuncture improves NKCA in animals and immuno-compromised humans. The purpose of the study was to determine whether 4-wks of acupuncture could prevent postexercise suppression of NKCA. Thirteen well-trained aerobic athletes were randomly assigned to either an acupuncture (ACU) or placebo (SHAM) group. All subjects completed two exercise sessions (60-min of cycling at 78% VO_2peak): prior to and after 4-wks of ACU/SHAM. NK cell number (CD3^-/56⁺) and activity (CD69 and CD107a) were quantified by flow cytometry before (PRE), immediately following (POST), and 2-h (2H) post exercise. Serum cortisol was determined by EIA. NK cell number, activity, and cortisol concentration were not altered by ACU. NK cell surface expression of CD107a was higher in the ACU group following 4-wks of acupuncture treatments (5.48 vs. 3.65 MFI, P = 0.022), however, this effect was abolished by exercise. In conclusion, ACU may alter selective aspects of resting NKCA; however, it does not appear to protect against the suppressive effects of strenuous aerobic exercise.