Variations of hematocrit ratio, urine volume and urinary sodium and potassiumm excretion have been studied after a water load with a two hour period of recumbency or upright position followed by furosemide infusion in normal healthy volunteers with previous diuretic therapy or without any pretreatment.
On the morning of the study, subjects of each group were instructed to take a usual breakfast allowed. They were ambulatory until arrival at the laboratory early morning and at 11:00 a.m., at which time the bladder emptied.
The subjects were given 500m1 of water and were recumbent or upright for the-remainder of the experiment. After 2 hr, urine specimens were taken and then, 40 mg of furosemide was given intravenously, and urine specimens were obtained at 30, 60, 90 and 120 minutes.
Urinary sodium and potassium concentrations were determined by means of a flame photometer, and urinary sodium and potassium excretion along with potassium to-sodium ratio were calculated.
From above data, effects of postural change and previous diuretic therapy on diu-retic patterns were studied.
The results were as follows;
1. Urine volume after water load or furosemide infusion of upright group was sig-nificantly decreased comparing with recumbency position group.
2. Amount of sodium excretion of upright group showed lower value than that of recumbency.
3. Potassium excretion of upright group and recumbency group didn´t show any di-fference, however K/Na excretion ratio of upright group was higher because of decrease of sodium excretion.
4. Diuretic effects of furosemide on urine volume, sodium and potassium excretion of subjects with previous diuretic therapy were decreased than that of control subjects.
5. Significant decrease of potassium excretion was showed in upright subject with previous diuretic therapy.
From the above results, author found postural change influenced significantly-the diuretic patterns.
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