Leppäluoto J, Arjamaa O, Vuolteenaho O, Ruskoaho H
Department of Physiology, University of Oulu, Finland.
J Appl Physiol (1985). 1991 Aug;71(2):716-20. doi: 10.1152/jappl.1991.71.2.716.
The effects of passive heat exposure on atrial natriuretic peptide (ANP) were studied in six healthy men staying in a Finnish sauna at +92 degrees C for 20 min. Their rectal temperature increased by 0.4 degrees C, and evaporative water loss was 0.92 +/- 0.14 (SD) kg. Heart rate and systolic blood pressure increased significantly during the 20-min exposure. Serum osmolality and plasma arginine vasopressin levels increased during the exposure, then declined, and increased significantly again at 90-120 min. Plasma renin activity and aldosterone increased by two- to fourfold in 20 min. Plasma ANP levels rose from 13 +/- 7 to 39 +/- 15 ng/l at 60 min and to 41 +/- 13 ng/l at 120 min (P less than 0.01 for both). We conclude that transient increases in heart rate and systolic blood pressure or changes in blood volume as inferred from the weight loss do not contribute to the increased plasma ANP levels observed after the heat exposure. Instead, increased secretions of pressor hormones could explain the elevated plasma ANP levels observed after the thermal stress.
研究了6名健康男性在芬兰桑拿房92摄氏度环境下停留20分钟时被动热暴露对心房利钠肽（ANP）的影响。他们的直肠温度升高了0.4摄氏度，蒸发失水量为0.92±0.14（标准差）千克。在20分钟的暴露过程中，心率和收缩压显著升高。血清渗透压和血浆精氨酸加压素水平在暴露期间升高，然后下降，并在90 - 120分钟时再次显著升高。血浆肾素活性和醛固酮在20分钟内增加了2至4倍。血浆ANP水平在60分钟时从13±7 ng/l升至39±15 ng/l，在120分钟时升至41±13 ng/l（两者P均小于0.01）。我们得出结论，心率和收缩压的短暂升高或由体重减轻推断出的血容量变化，并非热暴露后观察到的血浆ANP水平升高的原因。相反，升压激素分泌增加可以解释热应激后观察到的血浆ANP水平升高。
