EFFECT OF HEAT ACCLIMATIZATION ON INTRAVASCULAR RESPONSES TO ACUTE HEAT-STRESS IN MAN
EFFECT OF HEAT ACCLIMATIZATION ON INTRAVASCULAR RESPONSES TO ACUTE HEAT-STRESS IN MAN
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DOI：
10.1152/jappl.1976.41.5.708
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发表时间：
1976-01-01
影响因子：
3.3
通讯作者：
EDWARDS, RJ
中科院分区：
文献类型：
--
作者：
BONNER, RM;HARRISON, MH;EDWARDS, RJ
暴露在 48 度环境中 185 分钟的影响。 C db [干球]/33°C对 5 名男性受试者在热适应前后的 C wb [湿球]、血管内容量和渗透压以及血管内电解质、醛固酮和皮质醇浓度进行了研究。血细胞比容和血浆蛋白浓度的变化表明，在热暴露的前 35 分钟内发生了血液稀释，随后发生了血液浓缩。尽管血管内容量的这些变化不受驯化的影响，但热驯化后的血浆容量比之前增加了6.7%。血浆容量的增加与[Na]/[K]比率的升高相关。由于血浆渗透压降低，血管内扩张不能用电解质水平升高来解释。血浆醛固酮和皮质醇水平不受热适应的影响，尽管在高温下运动后两者都会升高。一旦达到盐平衡，肾上腺皮质就不再是维持热适应状态的重要因素。
The effects of a 185-min exposure to 48.degree. C db [dry bulb]/33.degree. C wb [wet bulb], on intravascular volume and osmolarity and on intravascular electrolyte, aldosterone and cortisol concentrations were studied in 5 male subjects before and after acclimatization to heat. Changes in the hematocrit and plasma protein concentration indicated that a hemodilution occurred during the first 35 min of the heat exposures, and that this was followed by a hemoconcentration. Although these changes in intravascular volume were not affected by acclimatization, the plasma volume after heat acclimatization was 6.7% greater than before. This increase in plasma volume was associated with an elevation in the ratio [Na]/[K]. Since plasma osmolarity decreased, the intravascular expansion could not be explained in term of elevated electrolyte levels. Plasma aldosterone and cortisol levles were not affected by heat acclimatization, although both were elevated following exercise in the heat. The adrenal cortex is not an important factor in maintaining a state of heat acclimatization once a salt balance is achieved.