Abstract

Some peptides are released with stress. We therefore examined effects of different exercise stress at low and moderate altitudes and after heat stress on beta-endorphin and endothelin in the human circulation. We also assessed longitudinally the effects of chronic exertion on beta-endorphin and the relationship to melatonin secretion in well-trained athletes. All peptides and melatonin increased after exercise, but the magnitude of this increase was age-dependent. Chronic exertion is associated with a decrease in exercise induced opioid release and in such individuals melatonin secreation is not beta-endorphin related. Long term high altitude exposure is associated with high beta-endorphin levels at rest. Arterial natriuretic factor and vasopressin is also released with exercise at moderate altitude. Endothelin, a powerful vasoconstrictor, is increased independent of type of exercise, duration and moderate hypoxia. Verf.-Referat