SERIAL DETERMINATIONS OF EXTRACELLULAR FLUID VOLUME USING THE RADIOSULPHATE SPACE METHOD

The fate of injected and ingested radiosulphate was investigated. The appearance of radiosulphate in bile was shown to be very rapid. Ingested radiosulphate was rapidly and completely absorbed, peak blood levels occurring at 1 to 2 hours.The sulphate space method of measuring extracellular fluid volume was studied and a method adopted requiring two serum samples taken at 1/2 and 6 hours following injection. This procedure provided a convenient means of making independent observations of extracellular fluid volume as often as four times a day in individual subjects. When values for the sulphate space were compared in the same individuals under conditions similar with respect to diet, activity, and time of day, the coefficient of variation was calculated to be ± 5.7% or about ± 1% of body weight. Values among well-nourished subjects with no known abnormalities of water or electrolyte balance gave a mean of 17.5% body weight with a range of 13.5 to 22% body weight. Values among obese subjects averaged 12.8% body weight.Studies of the diurnal variation of the sulphate space made every 6 hours throughout the day suggested that in man, under conditions of uniform intake and normal activity, there is a diurnal variation of extracellular fluid volume, higher values occurring at night.

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SERIAL DETERMINATIONS OF EXTRACELLULAR FLUID VOLUME USING THE RADIOSULPHATE SPACE METHOD

Canadian Journal of Biochemistry and Physiology ◽

10.1139/y63-058 ◽

1963 ◽

Vol 41 (1) ◽

pp. 497-510 ◽

Cited By ~ 1

Author(s):

Beverley Murphy ◽

J. B. Dossetor ◽

J. C. Beck

Keyword(s):

Body Weight ◽

Diurnal Variation ◽

Extracellular Fluid ◽

Time Of Day ◽

Fluid Volume ◽

Extracellular Fluid Volume ◽

Blood Levels ◽

Electrolyte Balance ◽

Serum Samples ◽

Space Method

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RENAL RESPONSE TO INFUSION OF ISOTONIC RINGER-LOCKE SOLUTION: EFFECT OF HYPOPHYSECTOMY

Journal of Endocrinology ◽

10.1677/joe.0.0740193 ◽

1977 ◽

Vol 74 (2) ◽

pp. 193-204

Author(s):

J. T. BAKER ◽

S. SOLOMON

Keyword(s):

Body Weight ◽

Proximal Tubule ◽

Volume Expansion ◽

Extracellular Fluid ◽

Fluid Volume ◽

Extracellular Fluid Volume ◽

Water Reabsorption ◽

Locke Solution ◽

Hypophysectomized Rats ◽

Distal Tubules

A comparison of the renal response to extracellular fluid volume expansion (5% body weight) was made between 25 normal and 25 chronically hypophysectomized rats. The extracellular fluid compartments averaged 25 ± 1% of body weight in both groups during control, fasted conditions. Extracellular fluid volume increased to 33 ± 1% in hypophysectomized and 34 ± 2% in normal rats during expansion, based on body weight. In addition, filtration fraction was similar in both normal and hypophysectomized rats during control (0·29 ± 0·03 and 0·26 ± 0·02 respectively) and infusion of Ringer–Locke solution (0·24 ± 0·05 and 0·27 ± 0·05 respectively). Thus our results cannot be explained by differences in the degree of expansion or failure to increase filtration in proportion to plasma flow. During infusion of isotonic Ringer–Locke solution, fractional water and sodium excretion both averaged 5·1% in normal rats and only 1·3% and 0·82% respectively in hypophysectomized rats. The ratio of single nephron to whole kidney filtration rate failed to increase as much in hypophysectomized compared with normal rats. Significant increases of fractional volume excretion occurred in both groups by the end of the accessible portion of the proximal tubule. However, fractional water reabsorption was depressed significantly more in normal (mean = 37%) than in hypophysectomized rats (mean = 19%). Fractional water reabsorption in distal tubules was similar in both groups during expansion. Arterial pressure was lower in hypophysectomized rats under control conditions, but showed similar changes during expansion compared with normal rats. Passage time decreased significantly in all groups after Ringer–Locke infusion, but remained prolonged in hypophysectomized rats in proximal and distal tubules. It is concluded that chronic hypophysectomy results in a less efficient renal excretion of volume and sodium chloride load. This inefficiency appears to be related in part to (1) failure of the proximal tubule to depress water reabsorption to a level equivalent to normal rats, and (2) failure to re-distribute flow to outer cortical glomeruli following extracellular fluid volume expansion in hypophysectomized rats.

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Restraint vs. hindlimb suspension on fluid and electrolyte balance in rats

Journal of Applied Physiology ◽

10.1152/jappl.1996.80.6.1993 ◽

1996 ◽

Vol 80 (6) ◽

pp. 1993-2001 ◽

Cited By ~ 13

Author(s):

F. Bouzeghrane ◽

S. Fagette ◽

L. Somody ◽

A. M. Allevard ◽

C. Gharib ◽

...

Keyword(s):

Plasma Volume ◽

Extracellular Fluid ◽

Fluid Volume ◽

Extracellular Fluid Volume ◽

Hindlimb Suspension ◽

Sodium Thiocyanate ◽

Electrolyte Balance ◽

Experimental Protocol ◽

Osmotic Load ◽

Atrial Natriuretic

To determine the effect of hindlimb suspension on body fluid volume, salt and water balance, and relevant hormones, two series of experiments were performed in an experimental protocol including periods of isolation (7 days), horizontal attachment (7 days), and suspension (14 days). 1) During the first experiment, water and electrolyte balance, arginine vasopressin (AVP), and guanosine 3',5'- cyclic monophosphate (cGMP) were determined in urine, atrial natriuretic peptide in plasma and atria, and renin concentration and AVP in plasma in 30 rats. 2) During the second experiment, blood volume and extracellular fluid volume were measured by a dilution technique (Evans blue and sodium thiocyanate) in another 30 rats. We observed a pronounced and early effect of horizontal attachment on the renal variables. After 48 h, diuresis (49%), natriuresis (44%), kaliuresis (36%), osmotic load (39%), creatinine (28%), and AVP excretion (155%) were significantly increased in attached rats (P < 0.05). There was no short-term (24-h) effect of suspension on urine flow and Na+, K+, creatinine, and AVP excretion, but the urine cGMP decreased significantly (45%; P < 0.05). Significant decreases in natriuresis, kaliuresis, urine creatinine, and osmotic load occurred in the suspension group 7 days after suspension. After the 14-day tail suspension, plasma volume and extracellular fluid volume measured in suspended rats were not different from isolated rat values, whereas plasma volume increased by 15% (P < 0.05) in the attached rats. Plasma immunoreactive plasma atrial natriuretic levels of suspended rats were significantly reduced by 35% vs. isolated rats (P < 0.001) and by 18% vs. attached rats (P < 0.05). By using this experimental protocol, the physiological alterations revealed that suspension produced some acute and long-term effects, but the fixation to the suspension device, restraint, and confinement have their own influence on fluid distribution and renal function.

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Role of renal arterial pressure in the regulation of extracellular volume in conscious dogs

Clinical Science ◽

10.1042/cs0820247 ◽

1992 ◽

Vol 82 (3) ◽

pp. 247-254 ◽

Cited By ~ 2

Author(s):

Gabriele Kaczmarczyk ◽

Klaus Schröder ◽

Dirk Lampe ◽

Rainer Mohnhaupt

Keyword(s):

Body Weight ◽

Arterial Pressure ◽

Sodium Excretion ◽

Urine Volume ◽

Extracellular Fluid ◽

Fluid Volume ◽

Extracellular Fluid Volume ◽

Conscious Dogs ◽

Central Venous ◽

Infusion Period

1. This study in conscious dogs examined the quantitative effects of a reduction in the renal arterial pressure on the renal homoeostatic responses to an acute extracellular fluid volume expansion. 2. Seven female beagle dogs were chronically instrumented with two aortic catheters, one central venous catheter and a suprarenal aortic cuff, and were kept under standardized conditions on a constant high dietary sodium intake (14.5 mmol of Na+ day−1 kg−1 body weight). 3. After a 60 min control period, 0.9% (w/v) NaCl was infused at a rate of 1 ml min−1 kg−1 body weight for 60 min (infusion period). Two different protocols were applied during the infusion period: renal arterial pressure was maintained at 102 ± 1 mmHg by means of a servo-feedback control circuit (RAP-sc, 14 experiments) or was left free (RAP-f, 14 experiments). 4. During the infusion period, in the RAP-sc protocol as well as in the RAP-f protocol, the mean arterial pressure increased by 10 mmHg, the heart rate increased by 20 beats/min, the central venous pressure increased by 4 cmH2O and the glomerular filtration rate (control 5.1 ± 0.3 ml min−1 kg−1 body weight, mean ± sem) increased by 1 ml min−1 kg−1. 5. Plasma renin activity [control 0.85 ± 0.15 (RAP-f) and 1.08 ± 0.23 (RAP-sc) pmol of angiotensin I h−1 ml−1] decreased similarly in both protocols. 6. Renal sodium excretion, fractional sodium excretion and urine volume increased more in the RAP-f experiments than in the RAP-sc experiments (P<0.05), renal sodium excretion from 8.2 to 70.1 (RAP-f) and from 7.7 to 47.4 (RAP-sc) μmol min−1 kg−1 body weight, fractional sodium excretion from 1.1 to 8.0 (RAP-f) and from 1.0 to 5.4 (RAP-sc)% and urine volume from 39 to 586 (RAP-f) and from 38 to 471 (RAP-sc) μl min−1 kg−1 body weight. 7. In the RAP-f experiments as well as in the RAP-sc experiments, urinary sodium excretion increased with expansion of the extracellular fluid volume, which increased by a maximum of 21% (fasting extracellular fluid volume: 206 ± 4 ml/kg body weight, six dogs, 28 days). 8. The increase in renal arterial pressure contributed significantly to the renal homoeostatic response, as 21% less urine and 31% less sodium were excreted when the extracellular fluid volume was expanded and the renal arterial pressure was kept constant below control pressure rather than being allowed to rise. The differences in sodium and water excretion were mainly due to the effect of renal arterial pressure on tubular reabsorption. However, the striking increase in sodium and urine excretion which occurred despite the reduction in renal arterial pressure emphasizes the importance of other homoeostatic factors involved in body fluid regulation.

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Dehydration in Infancy: Hospital Treatment

Pediatrics in Review ◽

10.1542/pir.11.5.139 ◽

1989 ◽

Vol 11 (5) ◽

pp. 139-143

Author(s):

Harold E. Harrison

Keyword(s):

Body Weight ◽

Intestinal Obstruction ◽

Plasma Volume ◽

Potassium Concentration ◽

Extracellular Fluid ◽

Fluid Volume ◽

Extracellular Fluid Volume ◽

Hospital Treatment ◽

Severe Dehydration ◽

Physiologic Function

Dehydration of a degree severe enough to require intravenous replacement of water and electrolytes indicates (1) depletion of extracellular fluid sodium and water to such an extent that reduction of plasma volume results or (2) distortion of the composition of extracellular fluid with consequent disturbance of physiologic function. Such distortion may be marked hypernatremia, severe depletion of extracellular bicarbonate, or disturbances of potassium concentration resulting in either hyperkalemia or hypokalemia. In addition, hypocalcemia or hypomagnesemia may require specific replacement of these ions. EXTRACELLULAR FLUID DEPLETION WITH HYPOVOLEMIA The most important cause of extracellular fluid depletion in terms of frequency is loss of gastrointestinal secretions through either diarrhea or vomiting. In persons with lower intestinal obstruction, sequestration of gastrointestinal secretions in dilated loops of intestine may be sufficient to cause dehydration in the absence of vomiting. In infants with diarrhea, the onset of vomiting usually is an indication for intravenous replacement of electrolyte and water deficits. Oliguria is also an important item of information, indicating that dehydration is severe enough to require parenteral fluids. It has been estimated that hypovolemia and reduced glomerular filtration with oliguria results when about one third of extracellular fluid volume has been lost. In an infant, the normal extracellular fluid volume is 25% of body weight; therefore, a loss of 8% of body weight as extracellular fluid would result in the manifestation of severe dehydration with reduction of plasma volume.

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Renal haemodynamics of cyclosporin A nephrotoxicity in children with juvenile dermatomyositis

Clinical Science ◽

10.1042/cs0810153 ◽

1991 ◽

Vol 81 (2) ◽

pp. 153-159 ◽

Cited By ~ 11

Author(s):

A. M. Peters ◽

J. Z. Heckmatt ◽

N. Hasson ◽

B. L. Henderson ◽

D. EL-Meleigy ◽

...

Keyword(s):

Glomerular Filtration Rate ◽

Cyclosporin A ◽

Glomerular Filtration ◽

Filtration Rate ◽

Extracellular Fluid ◽

Fluid Volume ◽

Extracellular Fluid Volume ◽

Blood Levels ◽

Filtration Fraction ◽

Trough Blood

1. Renal haemodynamics were monitored over an average period of 19 months in 17 children being treated with cyclosporin A. Sixteen had juvenile dermatomyositis and one had chronic polyneuropathy. The dose of cyclosporin A ranged from 2.3 to 8.3 mg day−1 kg−1 (median 4.1 mg day−1 kg−1). 2. Glomerular filtration rate (expressed in terms of extracellular fluid volume), renal blood flow (expressed as a fraction of cardiac output) and filtration fraction were measured by using 99mTc-labelled diethylenetriaminepenta-acetate. They were compared with the dosage and trough blood levels of cyclosporin A, and, in 15 patients receiving prednisolone in addition to cyclosporin A, with steroid dosage. 3. All 17 children had a renogram performed 6 months after starting cyclosporin A treatment. Nine of them also had a renogram before starting cyclosporin A treatment (baseline study), while 13, in addition to their renogram 6 months after starting cyclosporin A treatment, also had at least one further renogram. 4. Glomerular filtration rate/extracellular fluid volume fell slightly but significantly from 0.009 (sd 0.0013) before starting cyclosporin A treatment to 0.0085 (0.002) min−1 (P < 0.01) 6 months after cyclosporin A treatment in the nine children who underwent a baseline study. This was accompanied by a significant (P < 0.001) fall in filtration fraction from 0.108 (0.015) to 0.088 (0.014). However, renal blood flow/cardiac output showed no change. 5. In the 13 children studied beyond 6 months after starting cyclosporin A treatment, there was no further significant overall change in any renal haemodynamic variable. However, throughout this period, trough blood levels of cyclosporin A, which ranged from 20 to 258 ng/ml (median 67 ng/ml), correlated inversely with glomerular filtration rate/extracellular fluid volume, but not with renal blood flow/cardiac output. Furthermore, although a weak correlation between filtration fraction and trough blood levels of cyclosporin A did not reach statistical significance, sequential changes in filtration fraction correlated significantly with corresponding sequential changes in glomerular filtration rate/extracellular fluid volume. 6. We conclude that the predominant mechanism of renal impairment at these relatively low trough blood levels of cyclosporin A is a reversible reduction in filtration fraction.

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Body compostion in vivo. VIII. Some physiological implications with respect to extracellular fluid volume arising from the distribution of thiocyanate in sheep

Australian Journal of Agricultural Research ◽

10.1071/ar9650667 ◽

1965 ◽

Vol 16 (4) ◽

pp. 667 ◽

Cited By ~ 5

Author(s):

BA Panaretto

Keyword(s):

Body Weight ◽

Specific Activity ◽

Rumen Fluid ◽

Extracellular Fluid ◽

Fluid Volume ◽

Extracellular Fluid Volume

The distribution of [35S]-thiocyanate in sheep was studied. The specific activity in rumen fluid during the first 4 hr after injection was markedly less than in serum, and equilibration between rumen fluid and blood was not reached until 20–30 hr after injection. There were large urinary losses of the marker and approximately 50% of the dose was lost in 24 hr. Activity in rumen fluid and urine was due to [35S]-thiocyanate. The thiocyanate spaces, allowing for urinary losses, during the first 4 hr after injection were 25 –30% body weight, increasing to 35–40% body weight at 20–30 hr after injection. The physiological implications of the results with respect to measuring extracellular fluid volume in sheep are discussed.

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