Water and electrolyte changes in tropical Merino sheep exposed to dehydration during summer

1961 ◽  
Vol 12 (5) ◽  
pp. 889 ◽  
Author(s):  
WV Macfarlane ◽  
RJH Morris ◽  
B Howard ◽  
J McDonald ◽  
OE Budtz-Olsen
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Water Conservation ◽  
Renal Plasma Flow ◽  
Extracellular Volume ◽  
Urine Volume ◽  
Extracellular Fluid ◽  
Initial Increase ◽  
Fluid Loss ◽  
Plasma Urea

During three summers field studies were made of Merino wethers deprived of water while exposed to sun and to maximum air temperatures ranging from 84°F (29°C) to 10S°F (42°C) at Julia Creek, lat. 21° S. Evaporative cooling determined the rate and extent of water and electrolyte changes and produced a different pattern each year. Control of body temperature failed when 31% of body weight was lost by the end of 10 days without water. In hotter weather 5 days without water caused a 25% loss of body weight and in some sheep irreversible circulatory failure. In the course of dehydration, after an initial increase, the plasma and extracellular volume decreased up to 45% while concentrations of haemoglobin and plasma protein increased by 60%. In the plasma, potassium and sodium concentration increased less than that of haemoglobin. When 25% or more of weight was lost, plasma urea concentration rose to 136 mg/100 ml. Plasma osmolarity in some sheep reached 490 m-osmoles/l after 10 days. Urine volume fell after 2 days without water, and in a hot season less than 100 ml/24 hr was passed on the fourth or subsequent days. Concentrations increased over the first 4 or 5 days, reaching a maximum of 3.8 osmoles/l, then declined. Between half and two-thirds of the osmolarity was accountable to sodium and potassium salts. In rapid dehydration, more sodium was excreted than potassium. There was reduced sodium excretion when water was ingested after dehydration. Renal function studies in ewes indicated that filtration, renal plasma flow, and glucose reabsorption were reduced to half after 5 days without water in the heat. The chance of survival in dehydration appears to be increased by low rates of water loss in the first 3 days, together with high sodium and low potassium excretion. A full rumen, containing water up to 13% of body weight, could provide all the extracellular fluid loss. More than half of the weight loss appears, however, to come from intracellular sources. Extracellular fluid was drawn upon to a greater extent when the rate of dehydration was rapid, than in the cooler periods of slow weight loss. Survival in the sun without water depends upon insulation, water conservation, water reserves in rumen and extracellular fluid, the ability to adjust electrolyte concentrations, and the ability to maintain circulation with lowered plasma volume.

Role of Cyclic AMP in the Natriuresis of Extracellular Fluid Volume Expansion in the Dog

1977 ◽  
Vol 53 (6) ◽  
pp. 563-571
Author(s):  
R. M. Friedler ◽  
C. Descoeudres ◽  
K. Kurokawa ◽  
W.-J. Kreusser ◽  
S. G. Massry
Keyword(s):  
Body Weight ◽  
Cyclic Amp ◽  
Renal Vein ◽  
Volume Expansion ◽  
Renal Plasma Flow ◽  
Extracellular Volume ◽  
Extracellular Fluid ◽  
Net Production ◽  
Extracellular Volume Expansion

1. The effect of extracellular volume expansion (ECVE) on renal production of cyclic AMP was evaluated in 19 thyroparathyroidectomized dogs. ECVE was produced by the infusion of Ringer bicarbonate solution at a rate of 2 ml min−1 kg−1 body weight; cyclic AMP was measured in plasma obtained from the aorta and renal vein and in the urine. 2. During the natriuresis of ECVE urinary excretion of cyclic AMP, the clearance of cyclic AMP, net nephrogenous cyclic AMP added both to urine and to the renal vein and hence total nephrogenous cyclic AMP increased significantly. 3. This rise in net production of cyclic AMP and a significant natriuresis by the kidney persisted for 60–90 min after discontinuation of active ECVE and return of renal plasma flow to normal. 4. The results support the notion that an increase in the production of cyclic AMP by the kidney may play a role in the natriuresis of ECVE.

Energy cost, fluid and electrolyte balance in subarctic survival situations

1964 ◽  
Vol 19 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Terence A. Rogers ◽  
James A. Setliff ◽  
John C. Klopping
Keyword(s):  
Body Weight ◽  
Cold Exposure ◽  
Technical Assistance ◽  
Urine Volume ◽  
Extracellular Fluid ◽  
Electrolyte Balance ◽  
Acid Base Balance ◽  
Ambient Temperatures ◽  
Base Balance ◽  
The Cost

In two experiments a total of 12 men were subjected to 5 days of starvation under survival conditions in the winter subarctic. They wore flying clothing rated at 3.5 clo. The caloric cost, as calculated from oxygen consumption, was 2,300 kcal/m2 for the first day and 2,000 kcal/m2 for subsequent days at ambient temperatures of -30 C. At -10 C the cost of subsequent days fell to 1,500 kcal/m2. The subjects lost 8% of body weight but regained 5% body weight after 5 days refeeding on a barely maintenance diet. One-third of the original (8%) weight loss was due to an isotonic contraction of extracellular fluid. Changes in heart rate, pulse pressure, and hematocrit consistent with this fluid contraction were observed. Although the water intake did not exceed the 5-day urine volume (5 liters), the subjects did not experience thirst until after return to the warm. Note:(With the Technical Assistance of William P. Esser and Kermitt R. Skrettingland) caloric cost; cold exposure; electrolyte balance in starvation; fasting; fluid balance in starvation; IMP, integrating motor pneumotachograph; fat carbohydrate and protein catabolism in cold exposure and starvation; cold diuresis; sodium, potassium and acid-base balance in acute starvation Submitted on June 3, 1963

scholarly journals Effect of sodium in a rehydration beverage when consumed as a fluid or meal

1998 ◽  
Vol 85 (4) ◽  
pp. 1329-1336 ◽  
Author(s):  
Melinda L. Ray ◽  
Mark W. Bryan ◽  
Timothy M. Ruden ◽  
Shawn M. Baier ◽  
Rick L. Sharp ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Plasma Volume ◽  
Urine Volume ◽  
Body Weight Loss ◽  
Urine Osmolality ◽  
Sodium Concentration ◽  
Fluid Composition ◽  
Liquid Meal ◽  
The Impact

To investigate the impact of fluid composition on rehydration effectiveness, 30 subjects (15 men and 15 women) were studied during 2 h of rehydration after a 2.5% body weight loss. In a randomized crossover design, subjects rehydrated with water (H2O), chicken broth (CB: 109.5 mmol/l Na, 25.3 mmol/l K), a carbohydrate-electrolyte drink (CE: 16.0 mmol/l Na, 3.3 mmol/l K), and chicken noodle soup (Soup: 333.8 mmol/l Na, 13.7 mmol/l K). Subjects ingested 175 ml at the start of rehydration and 20 min later; H2O was given every 20 min thereafter for a total volume equal to body weight loss during dehydration. At the end of the rehydration period, plasma volume was not significantly different from predehydration values in the CB (−1.6 ± 1.1%) and Soup (−1.4 ± 0.9%) trials. In contrast, plasma volume remained significantly ( P < 0.01) below predehydration values in the H2O (−5.6 ± 1.1%) and CE (−4.2 ± 1.0%) trials after the rehydration period. Urine volume was greater in the CE (310 ± 30 ml) than in the CB (188 ± 20 ml) trial. Urine osmolality was higher in the CB and Soup trials than in the CE trial. Urinary sodium concentration was higher in the Soup and CB trials than in the CE and H2O trials. These results provide evidence that the inclusion of sodium in rehydration beverages, as well as consumption of a sodium-containing liquid meal, increases fluid retention and improves plasma volume restoration.

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

1992 ◽  
Vol 82 (3) ◽  
pp. 247-254 ◽  
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.

The Antidiuretic Effect of Chronic Hydrochlorothiazide Treatment in Rats with Diabetes Insipidus: Water and Electrolyte Balance

1982 ◽  
Vol 63 (6) ◽  
pp. 525-532 ◽  
Author(s):  
S. J. Walter ◽  
J. Skinner ◽  
J. F. Laycock ◽  
D. G. Shirley
Keyword(s):  
Diabetes Insipidus ◽  
Extracellular Volume ◽  
Urine Volume ◽  
Extracellular Fluid ◽  
Urinary Sodium Excretion ◽  
Sodium Concentration ◽  
Sodium Balance ◽  
Plasma Sodium ◽  
Electrolyte Balance ◽  
Antidiuretic Effect

1. The antidiuretic effect of hydrochlorothiazide in diabetes insipidus was investigated in rats with the hereditary hypothalamic form of the disease (Brattleboro rats). 2. Administration of hydrochlorothiazide in the food resulted in a marked fall in urine volume and a corresponding rise in osmolality. These effects persisted throughout the period of treatment (6–7 days). 3. Body weight and extracellular volume were significantly reduced in the thiazide-treated rats. 4. Hydrochlorothiazide caused an increase in urinary sodium excretion only on the first day of treatment. The resulting small negative sodium balance (in comparison with untreated rats) remained statistically significant for 2 days only. Thiazide-treated rats gradually developed a potassium deficit which was statistically significant from the fourth day of treatment. 5. Total exchangeable sodium, measured after 7 days of thiazide treatment, was not significantly different from that of untreated rats. However, plasma sodium was reduced in thiazide-treated animals, whereas erythrocyte sodium concentration was elevated. 6. It is concluded that the antidiuresis resulting from chronic hydrochlorothiazide administration is associated with a reduction in extracellular volume, but not with a significant overall sodium deficit. Hydrochlorothiazide appears to cause a redistribution of the body's sodium such that the amount of sodium in the extracellular fluid compartment is reduced.

scholarly journals Effects of intraruminal sodium chloride infusion on rumen and renal nitrogen and electrolyte dynamics in sheep

1986 ◽  
Vol 56 (2) ◽  
pp. 379-394 ◽  
Author(s):  
Ian R. Godwin ◽  
Vernon J. Williams
Keyword(s):  
Sodium Chloride ◽  
Food Intake ◽  
Turnover Rate ◽  
Volatile Fatty Acids ◽  
Renal Excretion ◽  
Renal Plasma Flow ◽  
Extracellular Fluid ◽  
Fractional Excretion ◽  
Water Excretion ◽  
Plasma Urea

1. Sheep were given 800 g low-protein roughage/d at 2 h intervals and infused intraruminally with 0, 500, 750, 1000, 1250, 1500 or 2000 mmol sodium chloride/d in 436 ml water. The digestibility of various food fractions and rumen ammonia, volatile fatty acids (VFA) and liquid turnover rate were measured, along with renal haemodynamics and the renal excretory patterns of nitrogen and electrolytes. Ad lib. food intake was determined during the infusion of 0 and 2000 mmol NaCl/d.2. Infusion of NaCl up to 750 mmol/d had virtually no effect on the indices measured, except water intake and water excretion. Infusion of greater amounts caused a step-wise decrease in the digestibility of organic matter (OM) and N. Rumen liquid turnover rate was increased substantially and rumen NH2, and VFA concentrations were decreased. Ad lib. food intake was not different when either 0 or 2000 mmol NaCl/d were infused into the rumen.3. The glomerular filtration rate and effective renal plasma flow (ERPF) were substantially increased after the infusion of 1250 mmol or more NaCl/d. Extracellular fluid volume was also increased. The renal excretion of urea and uric acid+allantoin (URAL) were decreased at the higher infusion rates but the fractional excretions of both these substances were enhanced. The excretion of sodium, chloride, calcium and magnesium were markedly increased with increasing salt infusion.4. The results suggest that high NaCl inputs into the rumen increase the rumen turnover rate, which in turn decreases the digestibility of OM, particularly N. This causes lower rumen NH3, and VFA concentrations. Plasma urea and URAL concentrations are also decreased and this causes lower renal excretion of these substances despite a much higher fractional excretion resulting from the greatly enhanced urine flow rate.5. When roughages low in N are given, NaCl intake should be kept below 20 mmol/kg body-weight per d to prevent a decline in the digestibility of the food and any consequent reduction in protein available to the sheep.

Head-down tilt and restraint on renal function and glomerular dynamics in the rat

1987 ◽  
Vol 63 (2) ◽  
pp. 505-513 ◽  
Author(s):  
B. J. Tucker ◽  
C. A. Mundy ◽  
M. G. Ziegler ◽  
C. Baylis ◽  
R. C. Blantz
Keyword(s):  
Renal Function ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Extracellular Volume ◽  
Extracellular Fluid ◽  
Conscious Rats ◽  
Single Nephron ◽  
Volume Measurements ◽  
Renal Micropuncture ◽  
Glomerular Ultrafiltration

A model utilizing 25 degree head-down tilt (HDT) and incorporated with chronic catheterization and renal micropuncture techniques in rats was employed to study alterations in renal function induced by HDT. Renal function and extracellular volume measurements were performed after 24 h, 4 days, and 7 days of HDT in conscious rats and compared with their own control measurements and to nontilted but similarly restrained rats. After 24 h HDT, glomerular filtration rate (GFR) increased 19 +/- 8% and renal plasma flow (RPF) increased 18 +/- 8% with increases in urine flow rate, Na+, and K+ excretion in conscious rats. These increases after 24 h were associated with an increase in extracellular volume of 16 +/- 3% (P less than 0.01). In the nontilted controls, there was a decrease in extracellular volume after 24 h of suspension. After 7 days of HDT, GFR was decreased by 7 +/- 1% (P less than 0.01), but RPF and extracellular fluid volume were not different from control values. However, RPF and GFR increased in the nontilted rats after 7 days. After 7 days of HDT renal micropuncture studies demonstrated that single-nephron filtration rate was also decreased from 43 +/- 2 to 31 +/- 3 nl/min (P less than 0.05) due solely to reductions in the glomerular ultrafiltration coefficient (0.11 +/- 0.01 to 0.07 +/- 0.01 nl.s-1 X mmHg-1, P less than 0.05). There was a dissociation between GFR and water and Na+ excretion at days 4 and 7 of HDT not observed in the nontilt restraint controls.

Diet and body weight loss in the rat during calorie restriction

1968 ◽  
Vol 46 (1) ◽  
pp. 101-107
Author(s):  
Peter B. Karch ◽  
John R. Beaton
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Body Fat ◽  
Resting Metabolic Rate ◽  
Urine Volume ◽  
Body Weight Loss ◽  
The Body ◽  
Male Rats ◽  
Calorie Intake ◽  
Isocaloric Diets

With adult male rats, experiments were carried out to ascertain the different effects, if any, of isocaloric diets high in carbohydrate, fat, or protein fed in restricted amounts of 9 g per rat per day on body weight loss and composition. It was observed that the nature of the diet did not alter rate, amount, or composition of body weight loss when fed in restricted amount for a period of 12 days. Further, the nature of the diet did not alter significantly the following parameters during restriction: water intake, urine volume, resting metabolic rate, spontaneous activity, urine and feces calorie values. In an experiment with hypothalamic-obese rats, the body weight loss and composition were not significantly different among the dietary-restricted groups. An important observation in this experiment was that as body fat decreased markedly owing to restricted feeding, body water increased markedly and counterbalanced approximately 60% of the potential weight loss due to the decrease in body fat. Our reported observations do not support the hypothesis that the composition of the diet may determine the rate and amount of body weight loss as a consequence of restricted food intake. They do support the hypothesis that the calorie intake, not the nature of the source of calories, determines the rate and amount of weight loss, at least for relatively short periods of food restriction.

Methohexital Impairs Osmoregulation

1995 ◽  
Vol 82 (6) ◽  
pp. 1396-1405. ◽  
Author(s):  
Maieli Kasner ◽  
Jochen Grosse ◽  
Martin Krebs ◽  
Gabriele Kaczmarczyk
Keyword(s):  
Body Weight ◽  
Antidiuretic Hormone ◽  
Surgical Stress ◽  
Extracellular Volume ◽  
Urine Volume ◽  
Blood Gases ◽  
Plasma Sodium ◽  
Plasma Osmolarity ◽  
Plasma Aldosterone Concentration ◽  
Arterial Blood

Background Anesthetic agents influence central regulations. This study investigated the effects of methohexital anesthesia on renal and hormonal responses to acute sodium and water loading in dogs in the absence of surgical stress. Methods Fourteen experiments (two in each dog) were performed in seven well-trained, chronically tracheotomized beagle dogs kept in highly standardized environmental and dietary conditions (2.5 mmol sodium and 91 ml water/kg body weight daily). Experiments lasted 3 h, while the dogs were conscious (7 experiments) or, after 1 h control, while they were anesthetized (7 experiments) with methohexital (initial dose 6.6 mg/kg body weight and maintenance infusion 0.34 mg.min-1.kg-1 body weight) over a period of 2 h. In both experiments, extracellular volume expansion was performed by intravenous infusion of a balanced isoosmolar electrolyte solution (0.5 ml.min-1.kg-1 body weight). Normal arterial blood gases were maintained by controlled mechanical ventilation. In another five dogs the same protocol was used, and vasopressin (0.05 mU.min-1.kg-1 body weight) was infused intravenously during methohexital anesthesia. Results Values are given as means. During methohexital anesthesia, mean arterial pressure decreased from 108 to 101 mmHg, and heart rate increased from 95 to 146 beats/min. Renal sodium excretion decreased; urine volume increased; and urine osmolarity decreased from 233 to 155 mosm/l, whereas plasma osmolarity increased from 301 to 312 mosm/l because of an increase in plasma sodium concentration from 148 to 154 mmol/l. Plasma renin activity, plasma aldosterone concentration, plasma atrial natriuretic peptide, and plasma antidiuretic hormone concentrations (range 1.8-2.8 pg/ml) did not change in either protocol. In the presence of exogenous vasopressin (antidiuretic hormone 3.3 pg/ml), water diuresis did not occur, and neither plasma osmolarity nor the plasma concentration of sodium changed. Conclusions Methohexital may impair osmoregulation by inhibiting adequate pituitary antidiuretic hormone release in response to an osmotic challenge.

scholarly journals Albumin and Furosemide versus Mannitol and Furosemide in the Treatment of Diuretic Resistant Oedema in Childhood Nephrotic Syndrome

2014 ◽  
Vol 38 (2) ◽  
pp. 74-78
Author(s):  
Syed Saimul Huque ◽  
Md Habibur Rahman ◽  
Golam Muin Uddin ◽  
Salma Jahan ◽  
Afroza Begum ◽  
...  
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Nephrotic Syndrome ◽  
Urine Volume ◽  
Single Daily Dose ◽  
Childhood Nephrotic Syndrome ◽  
Daily Dose ◽  
Group A ◽  
Study Population ◽  
Group B

Background: To treat resistant oedema in childhood nephrotic syndrome is a therapeutic dilemma. This study was carried out to compare the efficacy of mannitol & furosemide with that of albumin & furosemide in the treatment of diuretic resistant oedema in childhood nephrotic syndrome. Methodology: Forty children with “resistant oedema” due to idiopathic nephrotic syndrome at Paediatric Nephrology Department, Bangabandhu Sheikh Mujib Medical University (BSMMU) from September 2006 to April 2008 were enrolled in this descriptive cross sectional study. `Resistant oedema` was considered based on failure to achieve therapeutic response to diuretics or a weight loss of <1% body weight daily. All nephrotic syndrome patients with anasarca, age 1 year to 15 years of both sexes were hospitalized and were managed with fluid restriction, salt restriction and bed rest. Beside these 2 mg/kg/day oral furosemide or combination of furosemide and spironolactone, were given for 3 days to achieve desired diuresis. Those patients who did not get response were divided into two groups (Group-A, Group-B) in consecutive fashion. The Group- A study population, was with intravenous mannitol 0.5-1 gm/kg/day in single daily dose over 1-2 hrs followed by intravenous furosemide 1 mg/kg/day for 5 days. The Group-B study population was with intravenous albumin, 0.5 – 1 gm/ kg /day in single daily dose over 1-2 hrs followed by intravenous furosemide 1 mg/kg/day in every alternate day, total 3 doses. Efficacy of both groups of drugs was observed day to day by recording the follow-up chart. Results: Efficacy of treatment was evaluated by measuring weight loss and increment of urine volume. Much more increment of urine volume was occurred after albuminfurosemide infusion (1383±949.45ml vs 139.17±88.84ml) than in mannitol-furosemide infusion (928.13±359.61ml vs 151.88±67.15ml). But the difference between the two groups was not statistically significant. Body weight was reduced 13.74% in Mannitolfurosemide group. All other parameters like abdominal girth and complications of oedema reduction were similar with albumin & furosemide group. Conclusion: It is concluded that response to mannitol-furosemide combination is as effective as albumin with furosemide in the treatment of diuretic resistant oedema in children with nephrotic syndrome. However, new combination is less costly and may be more useful in our society. DOI: http://dx.doi.org/10.3329/bjch.v38i2.21139 Bangladesh J Child Health 2014; VOL 38 (2) : 68-73

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