Ashkenazi I, Epshtein Y
Medical Corps, Israel Defence Forces, Sackler School of Medicine, Tel-Aviv University, Israel.
Mil Med. 1998 Oct;163(10):687-91.
The purpose of this study was to determine the effect of a continuous 110-km march with a 20-kg backpack load on plasma volume and intravascular protein content. Twenty-two healthy male volunteers, aged 19 to 20 years (mean, 19.4 years), physically conditioned for continuous strenuous exercise, with a mean (+/- SD) maximal oxygen consumption of 59.1 (+/- 7.9) ml/kg/min, participated in the study. The march was performed under ambient conditions of 17 to 32 degrees C dry temperature and 45 to 85% relative humidity. Venous blood samples were obtained before, during, and after the march. The average calculated oxygen consumption during the march was about 30% of maximal oxygen consumption. Mean body weight loss was 3.4% of the premarch weight, mean water ingestion was 14,250 ml, and mean urine volume was 2,687 ml. Relative changes of plasma volume and total content of plasma protein were calculated from hematocrit ratio and hemoglobin concentration. A significant reduction (-6.1 +/- 1.7%, mean +/- SE) in plasma volume and a minimal elevation in intravascular protein content (1.6 +/- 2.5%) were observed during the march. During the first 24 hours of recovery, plasma volume was further reduced (-8.4 +/- 1.8%), with a significant reduction in protein content (-6.6 +/- 1.8%), mainly albumin (-9.3 +/- 1.7%). During the second day of recovery, peak elevations in plasma volume (3.7 +/- 1.4%) and protein content (6.0 +/- 1.6%) were observed. The changes in protein content were related to elevations in albumin (3.7 +/- 1.3%) and globulin (10.7 +/- 3.2%) content. The elevated plasma volume and protein content were also maintained 96 hours after the end of the march. Although the changes in plasma volume during the march were associated with changes in serum albumin and globulin content, during the recovery period there was association only with the changes in serum globulin content. The possible mechanism of these findings is discussed.
本研究的目的是确定背负20千克背包连续行军110公里对血浆容量和血管内蛋白质含量的影响。22名年龄在19至20岁（平均19.4岁）的健康男性志愿者参与了该研究，他们都具备持续剧烈运动的体能条件，平均（±标准差）最大耗氧量为59.1（±7.9）毫升/千克/分钟。行军在干燥温度为17至32摄氏度、相对湿度为45%至85%的环境条件下进行。在行军前、行军中和行军后采集静脉血样。行军期间计算得出的平均耗氧量约为最大耗氧量的30%。平均体重减轻为行军前体重的3.4%，平均饮水量为14250毫升，平均尿量为2687毫升。根据血细胞比容和血红蛋白浓度计算血浆容量和血浆蛋白总量的相对变化。行军期间观察到血浆容量显著减少（-6.1±1.7%，平均±标准误），血管内蛋白质含量略有升高（1.6±2.5%）。在恢复的头24小时内，血浆容量进一步减少（-8.4±1.8%），蛋白质含量显著降低（-6.6±1.8%），主要是白蛋白（-9.3±1.7%）。在恢复的第二天，观察到血浆容量（3.7±1.4%）和蛋白质含量（6.0±1.6%）达到峰值升高。蛋白质含量的变化与白蛋白（3.7±1.3%）和球蛋白（10.7±3.2%）含量的升高有关。行军结束96小时后，升高的血浆容量和蛋白质含量也得以维持。尽管行军期间血浆容量的变化与血清白蛋白和球蛋白含量的变化有关，但在恢复期仅与血清球蛋白含量的变化有关。本文讨论了这些发现的可能机制。
