OUTCOME OF EXTRACELLULAR VOLUME CHANGE--THE OLDEST OLD

老年人患病态钠紊乱的患病率增加 水的平衡。这是次要的许多年龄和疾病有关 潜在生理稳态机制的改变 调节细胞外液的体积和组成。审查 细胞外容积增加对身体功能的影响， 激素调节指数，我们正在研究健康的年轻人和老年人 志愿者的年龄从18岁到30岁，70岁及以上。 在吃了三天受控的正常钠饮食后， 志愿者接受24小时的四小时血液采样，用于心房 利钠肽水平（ANP），连续两次12小时尿 收集，和运动试验，在此期间，ANP，加压素， 去甲肾上腺素水平和肺毛细血管的无创估计 获得楔形压力。该研究重复了大约一个 一个月后，志愿者已经消耗了250 mEq（高）钠 饮食三天。数据分析将阐明 年轻人和老年人的内分泌、心血管和肾脏系统 当盐摄入量从正常到高变化时，久坐的志愿者。 心钠素分泌和钠排泄的日变化 还将对团体进行审查。

The elderly suffer an increased prevalence of morbid disorders of sodium and water balance. This is secondary to many age and disease related alterations in the underlying physiologic homeostatic mechanisms regulating extracellular fluid volume and composition. To examine the influence of increased extracellular volume on physical functioning and hormonal regulatory indices, we are studying healthy young and old volunteers ranging in age from 18 to 30 years and 70 years and older. After eating a controlled normal sodium diet for three days, each volunteer undergoes 24 hours of four-hourly blood sampling for atrial natriuretic peptide level (ANP), two consecutive 12-hour urine collections, and an exercise test, during which ANP, vasopressin, norepinephrine levels and non-invasive estimation of pulmonary capillary wedge pressures are obtained. The study is repeated approximately a month later after the volunteer has consumed a 250 mEq (high) sodium diet for three days. Data analysis will elucidate the relationship among the endocrine, cardiovascular and renal systems of young and old sedentary volunteers when salt intake is varied from normal to high. Diurnal variation of ANP secretion and sodium excretion between age groups will also be examined.