Severs Y, Brenner I, Shek P N, Shephard R J
Defence and Civil Institute of Environmental Medicine, Toronto, Ontario, Canada.
Eur J Appl Physiol Occup Physiol. 1996;74(3):234-45. doi: 10.1007/BF00377446.
This study examined the combined effects of heat stress and intermittent exercise on circulating leukocyte and sub-population cell counts. Using a randomized-block design, 11 healthy male subjects [mean (SD) age = 29.1 (3.0) years maximal oxygen consumption (VO2max) = 47.6 (6.1) ml/(kg.min)] were assigned to four conditions. Each subject exercised on a cycle ergometer at 50% VO2max (two 30-min bouts, with 45 min rest between), or acted as his own control by sitting at 23 degrees C, or at 40 degrees C, 30% relative humidity, for 3 h. Blood samples taken prior to, during, and after each rest and exercise bout, and at corresponding times when sitting were used for Coulter cell counter and flow cytometric analysis. Sitting conditions did not produce any significant immunological changes. Intermittent exercise induced a biphasic response of granulocytosis, monocytosis and lymphocytosis, with a return to baseline between exercise bouts. One hour following the second exercise bout, samples showed a consistent granulocytosis, monocytosis and lymphocytosis (CD3+, CD4+, CD8+ and CD19+ cell counts). The second exercise bout produced a larger response than the first, further exacerbated when exercising at 40 degrees C. We conclude there is a synergism between heat and exercise exposure. An increase in core temperature and exercise stress recruit leukocytes into the peripheral circulation, with potentiation of the response during a second bout of exercise. However, while the increase of core temperature remains moderate, the disturbance of immune function does not appear to have great clinical significance.
本研究考察了热应激和间歇运动对循环白细胞及亚群细胞计数的联合影响。采用随机区组设计，将11名健康男性受试者[平均（标准差）年龄 = 29.1（3.0）岁，最大耗氧量（VO2max）= 47.6（6.1）ml/（kg·min）]分为四种情况。每位受试者在功率自行车上以50%VO2max的强度进行运动（两次30分钟的运动时段，中间休息45分钟），或者在23摄氏度、40摄氏度、相对湿度30%的环境中静坐3小时作为自身对照。在每次休息和运动时段之前、期间及之后，以及静坐时的相应时间采集血样，用于库尔特细胞计数仪和流式细胞术分析。静坐条件未产生任何显著的免疫学变化。间歇运动诱导了粒细胞增多、单核细胞增多和淋巴细胞增多的双相反应，运动时段之间恢复到基线水平。第二次运动时段后1小时，样本显示持续的粒细胞增多、单核细胞增多和淋巴细胞增多（CD3 +、CD4 +、CD8 +和CD19 +细胞计数）。第二次运动时段产生的反应比第一次更大，在40摄氏度运动时进一步加剧。我们得出结论，热暴露和运动之间存在协同作用。核心体温升高和运动应激会使白细胞进入外周循环，在第二次运动时段反应增强。然而，虽然核心体温的升高保持适度，但免疫功能的紊乱似乎没有重大临床意义。
