Plasma volume and ion regulation during exercise after low- and high-carbohydrate diets.
Plasma volume and ion regulation during exercise after low- and high-carbohydrate diets.
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低碳水化合物和高碳水化合物饮食后运动期间的血浆容量和离子调节。
DOI：
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发表时间：
1994
影响因子：
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通讯作者：
G. Heigenhauser
中科院分区：
文献类型：
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作者：
M. Lindinger;L. Spriet;E. Hultman;T. Putman;R. McKelvie;L. Lands;N. Jones;G. Heigenhauser
This study compared plasma volume (PV) and ion regulation during prolonged exercise in control vs. glycogen-depleted (GD) conditions, with emphasis on the initial minutes of exercise. In two trials separated by 1-2 wk, four adult males cycled at 75% of peak oxygen consumption (VO2) until exhaustion (50 +/- 7 min for GD) or until the GD exhaustion time in the control trial. Blood was sampled from catheters placed in the brachial artery and retrograde in the femoral vein (fv). Arterial PV decreased rapidly and by 15 min PV was 83% (control) and 88% (GD) of initial. The decrease in PV was accompanied by a net osmotic flux of water from plasma and inactive tissues to contracting muscles. The significantly greater decrease in PV in control compared with GD was associated with a higher muscle lactate content (Lac-; 36 vs. 17 mumol/g dry wt, respectively). Increases in plasma [Cl-] and [Na+] were less than predicted from decreased PV, indicating net loss of these ions from the plasma compartment. Increases in arterial and fv [K+] were 50% greater than could be accounted for by decreased PV, corresponding with increased arterial and fv plasma K+ contents. The rapid net release of K+ and Lac- from contracting muscle during the first few minutes of exercise in both trials was abolished (control) or reversed (GD) within 15 min of beginning exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
