EFFECT OF INDOMETHACIN ON NK ACTIVITY OF PBMC

Abstract

126 Prostaglandin-induced impairment of natural killer cell activity (NK) has been implicated in the suppression of NK during recovery from moderate to high intensity endurance exercise. Transient suppression of NK may place the host at increased risk of infection. The purpose of this study was to investigate the effect of oral indomethacin, a prostaglandin inhibitor, on NK response of isolated peripheral blood mononuclear cells (PBMC) to high intensity endurance exercise. Ten, male distance runners completed one hour of treadmill running @85% VO2max under two conditions: IN (indomethacin, 150 mg day−1 for two days) and CON (no treatment). Trials were counter-balanced and separated by two weeks. NK (% lysis) was determined before (PRE), immediately after (POST) and 1.5 hours after completion of exercise (1.5P) using isolated PBMCs in a chromium release assay (51Cr, k562 target cells). PBMCs were incubated with target cells at four concentrations. No significant group effects or interactions were observed. Significant time effects revealed that NK was elevated POST (22.24 ± 2.76%; mean ± S.E.) relative to both PRE (8.06 ± 1.39%) and 1.5P (5.86 ± 1.06%). The percentage of NK cells (CD3−/16+/56+) was significantly higher POST (23.20 ± 1.53) relative to PRE (12.35 ± 1.55) and 1.5P (8.95 ± .90). Neither concentration nor distribution of NK cells was affected by 48 hours of indomethacin dosing. Indomethacin was not found to affect the NK response to acute, high-intensity endurance running.