Several methods for determining exchangeable sodium in human subjects by using the gammaray emitter Na22 (half-life 2.6 years) in conjunction with measurements of body radioactivity have previously been described (1-3). With these methods, it is possible to make repeated exchangeable sodium determinations over a period of several weeks or months after giving a single tracer dose of the radioiso...

1. Total body water, extracellular fluid, total exchangeable potassium and total exchangeable sodium were measured by the multiple isotope-dilution technique in eight patients with congestive cardiac failure. Measurements were made on each patient while in failure and then again after treatment and recovery. 2. Compared with five control subjects in whom the same measurements were made, patient...

Previous studies have suggested that angiotensin II and sodium can act as alternative mechanisms in maintaining high blood pressure in chronic renovascular hypertension, In the present study, exchangeable sodium was measured in rats in which angiotensin II has been confirmed or excluded as the main cause of the hypertension. To determine the degree of participation of angiotensin II in the main...

The body composition of patients with heart disease is acutely altered by surgical intervention. Interrelations and causes of the alterations have not been clear. Twenty patients were studied preoperatively and again 2 to 4 days after open intracardiac operations. In nine, measurements were made of the volumes of total body water, extracellular water, plasma, and red cells, and of the amounts o...

Eight normotensive and eight essential hypertensive humans were studied when on high and low sodium intake. Total 24-hr exchangeable body sodium, blood volume, serum sodium concentration, hematocrit, body weight, and mean arterial pressures, when the subjects were supine and upright, were measured. Plasma and nonplasma sodium fractions, nonplasma weight, and plasma, cell, and whole blood volume...

1. Standard radioisotope dilution techniques employing [3H]water and [22Na]sodium chloride have been used to determine the total body water and total exchangeable sodium of 20 male and 10 female normal Ghanaians (Africans) aged 19--25 years. 2. Lean body mass and total body fat are calculated as a percentage of body weight; the total exchangeable sodium values have been expressed in relation to...

Serial determinations of the exchangeable sodium content and sodium24 (Na24) space were made by the radioisotope dilution method in patients with congestive failure during the course of intensive therapy. In most instances, the decrease in body weight was too great to be accounted for solely on the basis of the change in sodium24 space or exchangeable sodium content. This excess weight loss is ...

Serial determinations of the exchangeable sodium content and sodium24 (Na24) space were made by the radioisotope dilution method in patients with congestive failure during the course of intensive therapy. In most instances, the decrease in body weight was too great to be accounted for solely on the basis of the change in sodium24 space or exchangeable sodium content. This excess weight loss is ...