Finberg J P, Berlyne G M
J Appl Physiol Respir Environ Exerc Physiol. 1977 Apr;42(4):554-8. doi: 10.1152/jappl.1977.42.4.554.
Plasma renin activity (PRA) and aldosterone concentration (PA) increased in eight men following a brief (30--40 min) heat exposure (50 degrees C dry bulb, 25 degrees C wet bulb) with light work. Sweat loss was less than 1% body weight. Plasma cortisol concentration was unchanged or decreased. In four subjects, a standard heat test was repeated in winter and summer (natural acclimatization). The increase in PRA and PA following heat exposure was less in summer than in winter. Four other subjects were artificially acclimated by daily work periods of 90 min at 50 degrees C for 7 days (artificial acclimation). Heat-induced elevation in PRA was considerably reduced by artificial acclimation, although postheat PA was reduced in only two of the four subjects. The small degree of sweat loss under the conditions of these experiments shows that circulating renin and aldosterone levels are increased in the heat even when a significant sodium deficit is not incurred.
八名男性在轻度活动下经历短暂（30 - 40分钟）的热暴露（干球温度50摄氏度，湿球温度25摄氏度）后，血浆肾素活性（PRA）和醛固酮浓度（PA）升高。出汗量少于体重的1%。血浆皮质醇浓度未改变或下降。在四名受试者中，在冬季和夏季重复进行了标准热试验（自然适应）。热暴露后PRA和PA的升高在夏季比冬季小。另外四名受试者通过在50摄氏度下每天工作90分钟，持续7天进行人工适应（人工适应）。人工适应使热诱导的PRA升高显著降低，尽管在四名受试者中只有两名受试者热暴露后的PA降低。在这些实验条件下出汗量较少表明，即使没有明显的钠缺乏，热环境中循环肾素和醛固酮水平也会升高。
