Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: December 10, 2000
Publication Date: March 7, 2001
Citation: Lukaski, H.C., Vanderpool, R.A., Johnson, P.E. 2001. Dietary exchangeable copper after exercise in men fed diets varying in copper content. The Federation of American Societies for Experimental Biology Journal. 15:A416. Technical Abstract: Exercise is a stressor that promotes mobilization of mineral elements from soft tissue storage depots particularly skeletal muscle. This study examined the hypothesis that alterations in dietary copper (Cu) intake affect exchangeable copper in blood and muscle. Nine men, aged 27 to 38 yr, resided on a metabolic unit and consumed whole food diets that provided adequate (1.5 mg Cu per 2500 kcal daily for 13 wk) then marginal (0.7 mg Cu per 2500 kcal for 7 wk) Cu intakes. 65**Cu, a stable isotope of Cu, was administered intravenously after 3 wk on each diet. Exchangeable Cu was measured as 65**Cu in plasma before and after controlled submaximal exercise (45 min at 70% peak work capacity) on an ergocycle. Muscle concentration of 65**Cu was determined twice, 3 d before exercise. Marginal dietary Cu was associated with a significant increase in heart rate (144+/-2 vs 138+/-2 bpm), ventilation (56+/-2 vs 62+/-2 L/min) and peak oxygen uptake (1.99+/-11 vs 1.69+/-10 L/min) during submaximal work. There was an interaction (p < 0.004) between dietary Cu and exercise; exchangeable Cu concentration after exercise decreased when dietary Cu was marginal and increased when dietary Cu was adequate. Skeletal muscle 65**Cu concentration increased (15+/-1 vs 10+/-1 ng/g; p < 0.04 when dietary Cu was marginal compared to adequate. These findings indicate that marginal dietary Cu adversely affects cardiorespiratory function during submaximal exercise and decreases the mobilization of Cu from skeletal muscle into blood plasma. Thus, exchangeable Cu represents a functional pool of body Cu that is conserved when dietary Cu is inadequate.