Water Balance and Kidney Function in Four Species of Rattus From Ecologically Diverse Environments.

1976 ◽  
Vol 24 (1) ◽  
pp. 7 ◽  
Author(s):  
PR Baverstock
Keyword(s):  
Drinking Water ◽  
Water Balance ◽  
Osmotic Pressure ◽  
Individual Variation ◽  
Water Deprivation ◽  
High Metabolic Rate ◽  
Sodium Potassium ◽  
Rattus Fuscipes ◽  
Microhabitat Preferences ◽  
Urine Concentrating Ability

While Rattus fuscipes survived only 4 days of water deprivation at 21�C, R. norvegicus, R. villosissimus and R. lutreolus survived 13-16 days. There was considerable inter-individual variation in the response of water-deprived R. villosissimus. Analysis of osmotic pressure, urea, sodium, potassium and chloride of both plasma and urine of rats with and without drinking water revealed that: (1) the abilities of R. norvegicus and R. villosissimus to tolerate water deprivation were due in large part to their abilities to produce highly concentrated urine; (2) R. lutreolus tolerated long periods of water deprivation not by urine-concentrating ability but by partly abandoning homeostasis and tolerating elevated levels of plasma solutes; (3) water-deprived R. fuscipes excreted large volumes of concentrated urine, possibly because their relatively high metabolic rate necessitated the excretion of excess metabolites. In all of the rats, urea constituted an unusually low proportion of the total osmotic pressure. The water-balance response of water-deprived rats is at variance with both their macrogeographical distribution and microhabitat preferences.

scholarly journals Ionic Regulation and Water Balance in the Aquatic Larva of Sialis Lutaria

1955 ◽  
Vol 32 (2) ◽  
pp. 353-382 ◽  
Author(s):  
J. SHAW
Keyword(s):  
Water Balance ◽  
Electrolyte Composition ◽  
Sodium Ions ◽  
Ionic Regulation ◽  
Sodium Potassium ◽  
Water Excretion ◽  
Factors Affecting ◽  
Osmotic Water ◽  
Saline Solutions ◽  
Aquatic Larva

1. The electrolyte composition of the blood, tissues and excretory fluid of the aquatic larvae of Sialis lutaria has been measured, and the regulation of the concentrations of sodium, potassium and chloride in the blood studied in detail. 2. In the normal larvae these ions are not present in the excretory fluid. Potassium and, perhaps, sodium are reabsorbed in the rectum but chloride is never present in the rectum. 3. If these ions are present in the outside medium they are taken into the larvae through the gut. The blood concentration is regulated by the excretion of these ions via the rectal fluid. Potassium is rapidly excreted but chloride tends to be retained in the blood. Sodium is removed more rapidly than chloride. 4. Water enters the larvae by osmosis through the cuticle, but can also be absorbed through the gut by osmosis or together with sodium ions. The water intake is balanced by excretion of rectal fluid. The factors affecting the rate of water excretion have been studied. 5. The larvae are unable to survive in hypertonic saline solutions. This is due to their inability to make good osmotic water loss or to produce a hypertonic excretory fluid.

Water Balance in Corixa Dentipes (Thoms.) (Hemiptera, Heteroptera)

1964 ◽  
Vol 41 (3) ◽  
pp. 609-619
Author(s):  
B. W. STADDON
Keyword(s):  
Water Balance ◽  
Osmotic Pressure ◽  
Water Intake ◽  
Ammonia Concentration ◽  
Ammonium Bicarbonate ◽  
Water Output

1. The water balance in Corixa dentipes (Thoms.) has been investigated under conditions of starvation in de-ionized water. 2. The rectal fluid was found to contain almost sufficient ammonium bicarbonate to account for the total osmotic pressure. It was invariably strongly hypotonic to the haemolymph. 3. The water output, as estimated by measuring the ammonia output and ammonia concentration of the rectal fluid, was shown to be appreciable but no connexion was found between the output of ammonia and of water. 4. Adults were shown to gain water by the mouth and some evidence was obtained that the cuticle may be an important route of water intake.

The role of the nasal glands in the survival of ducks (Anas platyrhynchos) exposed to hypertonic saline drinking water

1972 ◽  
Vol 50 (5) ◽  
pp. 611-617 ◽  
Author(s):  
E. L. Bradley ◽  
W. N. Holmes
Keyword(s):  
Drinking Water ◽  
Body Weight ◽  
Water Balance ◽  
Hypertonic Saline ◽  
Anas Platyrhynchos ◽  
Active Material ◽  
Plasma Concentrations ◽  
Plasma Osmolality ◽  
The Body ◽  
Nasal Glands

The supraorbital nasal glands were removed from the duck (Anas platyrhynchos) 1 week before experimentation. When sham-operated birds were given hypertonic saline drinking water (282 mM NaCl, 6 mM KCl) for 70 h they maintained their body weights and remained in positive water balance. When the ducks lacking nasal glands were similarly treated they became severely dehydrated, lost body weight at the rate of 5.59 ± 1.1 g/h and showed significant increases in the plasma concentrations of Na+, Cl−, K+, and total osmotically active material. When the glandless birds were given hypertonic saline drinking water, the disparity between the measured plasma osmolality and the osmolality calculated on the basis of the Na+, Cl−, and K+ concentrations in plasma increased two-fold. No such change in disparity between the measured and calculated osmolalities of plasma in the sham-operated birds was observed. Forty-eight hours after their return to a diet containing fresh drinking water, the birds without nasal glands regained some of the body weight they had lost and the plasma electrolyte concentrations were restored towards normal. It is concluded that in the absence of nasal glands, the kidney alone is incapable of maintaining positive water balance in ducks fed hypertonic saline as their only source of drinking water.

Water Balance and Titrated Pain Thresholds

1975 ◽  
Vol 37 (2) ◽  
pp. 487-494 ◽  
Author(s):  
W. E. Flynn ◽  
C. A. Schauer ◽  
W. H. Tedford
Keyword(s):  
Water Balance ◽  
Shock Intensity ◽  
Water Deprivation ◽  
Alternating Current ◽  
Dependent Measure ◽  
Pain Thresholds ◽  
Shock Frequency

Changes in sensitivity to electric foot shock were manipulated by subjecting 2 rats to 3 levels of water deprivation. Shock intensity was continuously titrated every 2 sec. through 20 increasing steps of alternating current. A bar-press reset the shock to its minimal value. The animals performed under conditions of 0, 21.5, and 45.5 hr. water deprivation. When water deprived, animals showed decreased sensitivity to shock. Frequency of bar-press responses at each of the 20 shock values served as the dependent measure. Findings were discussed in terms of competing techniques for measurement of analgesia.

Dehydration tolerance in Awassi fat-tailed sheep

1987 ◽  
Vol 65 (2) ◽  
pp. 363-367 ◽  
Author(s):  
S. Laden ◽  
L. Nehmadi ◽  
R. Yagil
Keyword(s):  
Drinking Water ◽  
Food Intake ◽  
Water Conservation ◽  
Water Deprivation ◽  
The Other ◽  
Water Restriction ◽  
Urine Excretion ◽  
Water Losses ◽  
Awassi Sheep ◽  
Active Substances

Young Awassi sheep were subjected to 5-d periods of complete water restriction in metabolic cages. During water deprivation there were steady declines in food intake and faeces and urine excretion. The blood haematocrit and urine and plasma osmolalities increased. There was a decline in blood and faecal water. As dehydration progressed, urinary excretion of osmotically active substances was greatly reduced. When drinking water was presented following 5 d of restriction it took 24 h to replace water losses and for urine to be excreted. Faecal water did not return to normal within 24 h. The sheep were as capable of withstanding dehydration as the other small desert ruminants that are mentioned in the literature. The dehydrated sheep relied on faecal and renal water conservation to survive. The sheep are not rapid replenishers of water losses, nor are they rapid reabsorbers of water, making their stay at water holes longer than that of goats.

Drinking-induced thermoregulatory panting in rehydrated sheep: influences of oropharyngeal/esophageal signals, core temperature, and thirst satiety

2009 ◽  
Vol 296 (6) ◽  
pp. R1881-R1888 ◽  
Author(s):  
M. J. McKinley ◽  
F. Weissenborn ◽  
M. L. Mathai
Keyword(s):  
Drinking Water ◽  
Body Temperature ◽  
Core Temperature ◽  
Heat Load ◽  
Water Deprivation ◽  
Saline Solution ◽  
Isotonic Saline ◽  
Cool Water ◽  
Rapid Fall

Dehydrated mammals conserve body water by reducing thermoregulatory evaporative cooling responses e.g., panting and sweating. Increased core temperature (Tc) may result. Following rehydration and correction of fluid deficits, panting and sweating commence. We investigated the role of oropharyngeal/esophageal, postabsorptive and thermal signals in the panting response, and reduced Tc that occurs when unshorn sheep drink water following water deprivation for 2 days (ambient temperature 20°C). Ingestion of water (at body temperature) resulted in increased respiratory rate (panting) and reduced Tc within 4 min that persisted for at least 90 min. Initially, a similar panting response and reduced Tc occurred following rehydration by drinking isotonic saline solution, but panting was not sustained after 20 min, and Tc began to rise again. Rehydration by intraruminal administration of water, without any drinking, resulted in delayed panting and fall in Tc. Intraruminal infusion of saline was ineffective. Rehydration by drinking cool water (20°C) resulted in a rapid fall in Tc without increased panting. Shorn sheep had lower basal Tc that did not increase during 2 days of water deprivation, and they did not pant on rehydration by drinking water. Our results indicate that signals from the oropharyngeal and/or esophageal region associated with the act of drinking play a crucial role in the initial 20–30 min of the panting response to rehydration. Postabsorptive factors most likely reduced plasma tonicity and cause continued panting and further reduction in Tc. Tc also influences rehydration-induced panting. It occurs only if sheep incur a heat load during bodily dehydration.

Effect of water deprivation on feed intake, nutrient digestibility and nitrogen retention in sheep

1976 ◽  
Vol 86 (2) ◽  
pp. 431-433 ◽  
Author(s):  
N. P. Singh ◽  
T. More ◽  
K. L. Sahni
Keyword(s):  
Adverse Effect ◽  
Drinking Water ◽  
Feed Intake ◽  
Water Deprivation ◽  
Nitrogen Retention ◽  
Nutrient Digestibility ◽  
Sheep Grazing ◽  
Influence Of Water ◽  
Wool Yield ◽  
Sheep Production

The problem of sheep grazing in the deserts of Rajasthan is that animals do not get drinking water for 2–3 days at a time. Studies carried out at this Institute, on water deprivation in sheep, have indicated that sheep deprived of water for 72 h did not show any adverse effect on wool yield, in spite of the fact that water deprivation reduced feed intake (More & Sahni, 1972). The present experiment is a part of extensive studies carried out on water deprivation with particular reference to sheep production. The paper describes the influence of water deprivation on nutrient digestibility and nitrogen retention in sheep.

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