Gaebelein C J, Senay L C, Ladd C M
Eur J Appl Physiol Occup Physiol. 1985;54(5):506-10. doi: 10.1007/BF00422961.
Although the vascular volume response of hypertensive men during exercise has been rather well characterized, the effect of resting heat exposure in this patient population has not been examined. This was done in the present report in seven men with high blood pressure (BP) (i.e., diastolic pressure greater than 12 kPa (90 mmHg) upon initial interview) and 5 normotensive control subjects. 50 min after each subject had consumed an amount of water equal to 1% of his body weight, he reclined on a cot. 10 min later the subject was carried into an environmental chamber equilibrated at Tdb = 45 degrees C, Twb = 28 degrees C. Free-flowing venous blood samples were obtained from a cubital vein, and BP and heart rate were measured, before the heat exposure and at 15 min intervals during the experiment. Within 30 min systolic, diastolic and mean BP of the high BP subjects had decreased to normal levels; no BP changes were detected in normotensive subjects. Accompanying this depressor response was an exaggerated elevation in plasma glucose concentration. No alterations were found with haematocrit, plasma osmolality or electrolytes, or total protein and albumin. The data suggest that heat exposure may have been more stressful for the subjects with high BP than for their controls. This finding implies that phasic depressor responses may be as important as phasic pressor episodes in the aetiology of established essential hypertension.
虽然运动期间高血压男性的血管容量反应已得到较好的描述，但静息热暴露对该患者群体的影响尚未得到研究。本报告对7名高血压男性（即初次就诊时舒张压大于12 kPa（90 mmHg））和5名血压正常的对照受试者进行了此项研究。在每位受试者饮用相当于其体重1%的水量50分钟后，让其躺在帆布床上。10分钟后，将受试者带入温度为干球温度（Tdb）=45℃、湿球温度（Twb）=28℃的环境舱。在热暴露前以及实验期间每隔15分钟，从肘静脉采集自由流动的静脉血样，并测量血压和心率。在30分钟内，高血压受试者的收缩压、舒张压和平均血压降至正常水平；血压正常的受试者未检测到血压变化。伴随这种降压反应的是血浆葡萄糖浓度的过度升高。血细胞比容、血浆渗透压或电解质、总蛋白和白蛋白均未发现改变。数据表明，热暴露对高血压受试者可能比对其对照受试者压力更大。这一发现意味着，在已确诊的原发性高血压病因中，阶段性降压反应可能与阶段性升压发作同样重要。
