N-acetylcysteine attenuates oxidative burst by neutrophils in response to ergometer rowing with no effect on pulmonary gas exchange

This study evaluated whether the reduction of the neutrophil oxidative burs t by N-acetylcysteine improves pulmonary gas exchange during a six minute m aximal ergometer row. Healthy trained oarsmen were double-blinded randomize d to either N-acetylcysteine (6 g daily for three days) or placebo groups. As determined by the relative changes of the zymosan-stimulated luminol-enh anced chemiluminescence response, N-acetylcysteine suppressed the exercise- induced enhanced neutrophil oxidative burst response to rowing (-7 +/- 6 % vs. 17 +/- 8 %: P < 0.05). This was the case although the concentration of neutrophils remained similarly elevated above the pre-exercise level in bot h trials (to 5.4 +/- 0.5 vs. 5.9 +/- 0.6 x 10(9) cells x l(-1), respectivel y, P > 0.05). In the placebo and N-acetylcysteine groups, pulmonary ventila tion increased and the arterial CO, partial pressure decreased to the same extent during exercise. Also, at the end of exercise the arterial O-2 parti al pressure (77 +/- 1 vs. 78 +/- 1 mmHg), haemoglobin O-2 saturation (92 +/ - 1 % vs. 93 +/- 1 %) and O-2 uptake (5.0 +/- 0.2 vs. 4.9 +/- 0.21 x min(-1 )) were not significantly affected by N-acetylcysteine, Equally, two hours after exercise, the pulmonary diffusion capacity was reduced by 7 +/- 2% be low the pre-exercise with no significant influence of N-acetylcysteine. We conclude that the neutrophil oxidative burst to exercise does not influence pulmonary gas exchange during and after maximal rowing.