Both physical fitness and acute exercise regulate nitric oxide formation in healthy man. Jungersten, Lennart, Anneli Ambring, Bjsrn Wall, and Ke Wennmalm. Department of Clinical Physiology, Gsteborg University, Sahlgrenska University Hospital, S-413 45 Gsteborg, Sweden
APStracts 3:0522A, 1996.
We analyzed nitrate, a major stable end-product of NO metabolism in vivo, in plasma and urine from groups of healthy subjects with different working capacity. Resting plasma nitrate was higher in athletic subjects than in non-athletic controls (45+/-2 vs. 34+/-2 [mu]mol/L; mean+/-SE, p<0.01). In other subjects, both the resting plasma nitrate level (r = 0.53; p<0.01) and the urinary excretion of nitrate at rest (r = 0.46; p<0.01) correlated to the subjects peak work rate, as determined by bicycle ergometry. Two hours of physical exercise elevated plasma nitrate by 18+/-4 (p<0.01) and 16+/-6 (p<0.01) %, respectively, in athletes and non-athletes, as compared to resting nitrate before exercise. We conclude that physical fitness and formation of NO at rest are positively linked to each other. Furthermore, a single session of exercise elicits an acute elevation of NO formation. The observed positive relation between physical exercise and NO formation may help to explain the beneficial effects of physical exercise on cardiovascular health.

Received 25 June 1996; accepted in final form 4 November 1996.
APS Manuscript Number A596-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996