Antioxidant status and lipid peroxidation following short-term maximal exercise in trained and untrained humans. Ortenblad, Niels, Klavs Madsen, Mogens S. Djurhuus. Department of Physical Education, University of Odense, Campusvej 55, 5230 Odense M, Denmark and Dept. of Clinical Chemistry, Odense University Hospital, 5000 Odense C, Denmark
APStracts 3:0435R, 1996.
The purpose of the present study was to measure blood and muscle antioxidant status in untrained and jump-trained humans. In addition, we evaluated the possible occurrence of free radical mediated muscle damage following a series of jumping - an exercise that previously has been shown to induce extreme muscle soreness in untrained individuals. Eight untrained and 8 jump-trained males made 6 bouts of 30 sec continuous jumping, separated by 2 min of rest (modified Bosco test). Blood samples were taken at rest, immediately, 1, 2 and 24 h following the test. Muscle biopsies in vastus lateralis were taken at rest and 24 h post-exercise. We found significantly higher activities of the muscle antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione reductase (GR) and manganese SOD (MnSOD), in jump trained compared to untrained subjects at rest. There were, however, no significant differences in blood antioxidant enzyme activity or in muscle catalase activity between the two groups. Creatine kinase (CK) increased significantly (P < 0.0001) 24 hours following exercise bouts (from a mean +/- SD value of 104 +/- 29 IU.l-1 to 2241 +/- 4628 IU.l-1) in untrained individuals, whereas the values remained unchanged in the trained individuals. Plasma and muscle malonaldehyde (MDA), following intensive exercise were not significantly different from resting levels. These data suggest that high intensive training, as jumping, elevates the activity of SOD and the coupled enzymes GPX and GR in muscle tissue, but other antioxidants remains unchanged. High -intensive exercise induces muscle enzyme leakage in untrained humans, but lipid peroxidation, measured as changes in MDA, was, however, not different in the two groups despite the varied muscle antioxidant enzyme levels.

Received 17 November 1995; accepted in final form 8 October 1996.
APS Manuscript Number R724-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996