Sassard J, Vincent M, Annat G, Bizollon C A
J Clin Endocrinol Metab. 1976 Jan;42(1):20-7. doi: 10.1210/jcem-42-1-20.
Cardiovascular parameters, hematocrit (Ht), plasma electrolytes, renin activity (PRA) and aldosterone concentration (PAC) were measured in 12 normal human subjects (6 males and 6 females) eating an ad lib diet. At 8 AM, volunteers assumed the following postural changes: 1 hour supine, then 2 hours upright and finally 1 hour supine. Orthostatism induced the following changes: heart rate, systolic and diastolic blood pressure increased immediately; Ht rose significantly at the 5th min in males but not in females; Plasma sodium showed no variations but potassium increased after 30 min; PRA rose significantly at the 5th min and, after 120 min of orthostatism, was found to be 3 times greater than its value after recumbency; and PAC increased significantly at the 15th min and exhibited a plateau 4.5 times its basal values after 90 min of upright posture. When subjects returned to the supine position all the parameters, except PAC decreased. During active orthostatism, a significant correlation was found between PAC and plasma potassium, but correlation was closer between PAC and PRA and between PAC and PRA + potassium. It can be concluded that the renin-angiotensin system is a more potent stimulus for aldosterone secretion than plasma potassium in normal man assuming postural changes. The results presented here can be applied to the development of a short posture test in non-hospitalized patients.
在12名自由饮食的正常人类受试者（6名男性和6名女性）中测量了心血管参数、血细胞比容（Ht）、血浆电解质、肾素活性（PRA）和醛固酮浓度（PAC）。上午8点，志愿者进行了以下体位变化：仰卧1小时，然后直立2小时，最后再仰卧1小时。直立位引起了以下变化：心率、收缩压和舒张压立即升高；男性在第5分钟时Ht显著升高，而女性则没有；血浆钠没有变化，但钾在30分钟后升高；PRA在第5分钟时显著升高，直立位120分钟后，发现其值是卧位后值的3倍；PAC在第15分钟时显著升高，直立位90分钟后呈现出比基础值高4.5倍的平台期。当受试者恢复到仰卧位时，除PAC外的所有参数均下降。在主动直立位期间，发现PAC与血浆钾之间存在显著相关性，但PAC与PRA之间以及PAC与PRA+钾之间的相关性更密切。可以得出结论，在进行体位变化的正常男性中，肾素-血管紧张素系统对醛固酮分泌的刺激比血浆钾更有效。这里呈现的结果可应用于非住院患者短体位试验的开发。
